Clam Anti-Virus ClamAV CAB文件处理拒绝服务漏洞

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漏洞ID 1197404 漏洞类型 资源管理错误
发布时间 2005-11-05 更新时间 2008-12-23
CVE编号 CVE-2005-3501 CNNVD-ID CNNVD-200511-127
漏洞平台 N/A CVSS评分 4.3
|漏洞来源
https://cxsecurity.com/issue/WLB-2005110015
http://www.cnnvd.org.cn/web/xxk/ldxqById.tag?CNNVD=CNNVD-200511-127
|漏洞详情
ClamAntiVirus(ClamAV)是免费而且开放源代码的防毒软件。ClamAntiVirus(ClamAV)0.87.1之前版本libmspack程序库(mspack)的cabd.c中的cabd_find函数,可让远程攻击者通过特制的CAB文件(可导致调用零长度的cabd_find)使系统拒绝服务(无限循环)。
|漏洞EXP
Clam AntiVirus Cabinet-file handling Denial of Service Vulnerability

iDEFENSE Security Advisory 11.04.05
http://www.idefense.com/application/poi/display?type=vulnerabilities
November 4, 2005

I. BACKGROUND

Clam AntiVirus is a GPL anti-virus toolkit for Unix.

II. DESCRIPTION

Remote exploitation of a design error in Clam AntiVirus ClamAV allows
attackers to cause a denial of service (DoS) condition.

The vulnerability specifically exists with the libmspack library, which
is included in ClamAV. The vulnerability can be found in the cabd_find
function within mspack/cabd.c:

for (offset = 0; offset < flen; offset += length) {
    length = flen - offset;

[... read length from file ...]

for (p = &buf[0], pend = &buf[length]; p < pend; ) {
      switch (state) {
        [ ... ]
        case 19:
=> header has been completely read, cablen has been read from bytes 8-11

[...]

/* likely cabinet found -- try reading it */
          cab = sys->alloc(sys, sizeof(struct mscabd_cabinet_p); => an
mscabd_cabinet_p entry will be allocated each time

/* cabinet read correctly! */
          offset = caboff + cablen;
=> if cablen (and caboff) == 0, offset will be equal to 0

[...]

/* restart search */
          [...]
          length = 0;
          p = pend;
          state = 0;
=> if offset == 0, we will restart at the beginning of the file =>
(because length == 0, so offset will still be zero in the next
  iteration)
          break;
      }
    }
  }

If this function is called with a length value of zero, an infinite loop
occurs. The comments above explain the scenario.

III. ANALYSIS

Successful exploitation requires an attacker to send a specially
constructed CAB file through a mail gateway or personal anti-virus
client utilizing the ClamAV scanning engine.

The infinite loop will cause the ClamAV software to use all available
processor resources, resulting in a denial of service or severe
degradation of system performance. Ultimately, the OOM handler will
terminate a task in order to alleviate the stress on the system.

IV. DETECTION

iDEFENSE has confirmed this vulnerability on ClamAV 0.86.1. All previous
versions are suspected vulnerable to this issue.

V. WORKAROUND

Archive file analysis can be disabled (--no-archive) but this can have
severe impacts on the virus detection functionality.

VI. VENDOR RESPONSE

The vendor has released clamav 0.87.1 to address this vulnerability. It
is available for download at:

http://prdownloads.sourceforge.net/clamav/clamav-0.87.1.tar.gz?download

VII. CVE INFORMATION

A Mitre Corp. Common Vulnerabilities and Exposures (CVE) number has not
been assigned yet.

VIII. DISCLOSURE TIMELINE

10/07/2005  Initial vendor notification
10/12/2005  Initial vendor response
11/04/2005  Coordinated public disclosure

IX. CREDIT

The discoverer of this vulnerability wishes to remain anonymous.

Get paid for vulnerability research
http://www.idefense.com/poi/teams/vcp.jsp

Free tools, research and upcoming events http://labs.idefense.com

X. LEGAL NOTICES

Copyright (c) 2005 iDEFENSE, Inc.

Permission is granted for the redistribution of this alert
electronically. It may not be edited in any way without the express
written consent of iDEFENSE. If you wish to reprint the whole or any
part of this alert in any other medium other than electronically, please
email customerservice (at) idefense (dot) com [email concealed] for permission.

Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
of the information constitutes acceptance for use in an AS IS condition.
There are no warranties with regard to this information. Neither the
author nor the publisher accepts any liability for any direct, indirect,
or consequential loss or damage arising from use of, or reliance on,
this information.
|参考资料

来源:IDEFENSE
名称:20051104ClamAntiVirusCabinet-filehandlingDenialofServiceVulnerability
链接:http://www.idefense.com/application/poi/display?id=334&type=vulnerabilities
来源:VUPEN
名称:ADV-2005-2294
链接:http://www.frsirt.com/english/advisories/2005/2294
来源:sourceforge.net
链接:http://sourceforge.net/project/shownotes.php?release_id=368319
来源:SECUNIA
名称:17434
链接:http://secunia.com/advisories/17434
来源:BID
名称:15317
链接:http://www.securityfocus.com/bid/15317
来源:OSVDB
名称:20484
链接:http://www.osvdb.org/20484
来源:MANDRIVA
名称:MDKSA-2005:205
链接:http://www.mandriva.com/security/advisories?name=MDKSA-2005:205
来源:GENTOO
名称:GLSA-200511-04
链接:http://www.gentoo.org/security/en/glsa/glsa-200511-04.xml
来源:DEBIAN
名称:DSA-887
链接:http://www.debian.org/security/2005/dsa-887
来源:SECTRACK
名称:1015154
链接:http://securitytracker.com/id?1015154
来源:SREASON
名称:150
链接:http://securityreason.com/securityalert/150
来源:SECUNIA
名称:17559
链接:http://secunia.com/advisories/17559
来源:SECUNIA
名称:17501
链接:http://secunia.com/advisories/17501
来源:S