Vulnerability identifier: #VU68362

Vulnerability risk: Low

CVSSv3.1: 3.2 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2008-5161

CWE-ID: CWE-755

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
OpenSSH
Server applications / Remote management servers, RDP, SSH

Vendor: OpenSSH

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

Error handling in the SSH protocol in (1) SSH Tectia Client and Server and Connector 4.0 through 4.4.11, 5.0 through 5.2.4, and 5.3 through 5.3.8; Client and Server and ConnectSecure 6.0 through 6.0.4; Server for Linux on IBM System z 6.0.4; Server for IBM z/OS 5.5.1 and earlier, 6.0.0, and 6.0.1; and Client 4.0-J through 4.3.3-J and 4.0-K through 4.3.10-K; and (2) OpenSSH 4.7p1 and possibly other versions, when using a block cipher algorithm in Cipher Block Chaining (CBC) mode, makes it easier for remote attackers to recover certain plaintext data from an arbitrary block of ciphertext in an SSH session via unknown vectors.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

OpenSSH: 4.7p1

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External links
http://isc.sans.org/diary.html?storyid=5366
http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10705
http://lists.apple.com/archives/security-announce/2009/Nov/msg00000.html
http://marc.info/?l=bugtraq&m=125017764422557&w=2
http://openssh.org/txt/cbc.adv
http://osvdb.org/49872
http://osvdb.org/50035
http://osvdb.org/50036
http://rhn.redhat.com/errata/RHSA-2009-1287.html
http://secunia.com/advisories/32740
http://secunia.com/advisories/32760
http://secunia.com/advisories/32833
http://secunia.com/advisories/33121
http://secunia.com/advisories/33308
http://secunia.com/advisories/34857
http://secunia.com/advisories/36558
http://sunsolve.sun.com/search/document.do?assetkey=1-66-247186-1
http://support.apple.com/kb/HT3937
http://support.attachmate.com/techdocs/2398.html
http://support.avaya.com/elmodocs2/security/ASA-2008-503.htm
http://www.cpni.gov.uk/Docs/Vulnerability_Advisory_SSH.txt
http://www.kb.cert.org/vuls/id/958563
http://www.rtpro.yamaha.co.jp/RT/FAQ/Security/CPNI957037.html
http://www.securityfocus.com/archive/1/498558/100/0/threaded
http://www.securityfocus.com/archive/1/498579/100/0/threaded
http://www.securityfocus.com/bid/32319
http://www.securitytracker.com/id?1021235
http://www.securitytracker.com/id?1021236
http://www.securitytracker.com/id?1021382
http://www.ssh.com/company/news/article/953/
http://www.vupen.com/english/advisories/2008/3172
http://www.vupen.com/english/advisories/2008/3173
http://www.vupen.com/english/advisories/2008/3409
http://www.vupen.com/english/advisories/2009/1135
http://www.vupen.com/english/advisories/2009/3184
http://exchange.xforce.ibmcloud.com/vulnerabilities/46620
http://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05157667
http://kc.mcafee.com/corporate/index?page=content&id=SB10106
http://kc.mcafee.com/corporate/index?page=content&id=SB10163
http://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11279

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.