839 : OpenSSH PAMAuthenticationViaKbdInt Challenge-Response Remote Overflow
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Views This Week	Views All Time	Added to OSVDB	Last Modified	Modified (since 2008)	Percent Complete
24	1924	over 9 years ago	over 2 years ago	1 times	85%

Timeline

Disclosure Date
2002-06-26

Description

A remote overflow exists in OpenSSH when using PAM modules that use interactive keyboard authentication such as PAMAuthenticationViaKbdInt. OpenSSH fails to limit a buffer of the number of responses received in its challenge-response authentication code, resulting in a pre-authentication buffer overflow. With a specially crafted request, an attacker can cause the sshd daemon to execute arbitrary code on this host, resulting in a loss of confidentiality, integrity, and/or availability.

Classification

Location: Remote / Network Access
Attack Type: Input Manipulation
Impact: Loss of Integrity
Disclosure: OSVDB Verified

Solution

Upgrade to version 3.4 or higher, as it has been reported to fix this vulnerability. It is also possible to correct the flaw by applying the vendor-supplied patch, or by disabling support for SSHv2 (not recommended).

Products

OpenSSH	OpenSSH	2.3.1
		2.5x
		2.9x
		3.0x
		3.1x
		3.2x
		3.3x

References

CVE ID: 2002-0640 (see also: NVD)
CERT VU: 369347
Bugtraq ID: 5093
Related OSVDB ID: 6245
CERT: CA-2002-18
Other Advisory URL: http://bvlive01.iss.net/issEn/delivery/xforce/alertdetail.jsp?oid=20584
Vendor Specific Advisory URL: http://www.debian.org/security/2002/dsa-134
http://www.linuxsecurity.com/advisories/other_advisory-2177.html
http://www.openssh.com/txt/preauth.adv
http://www.suse.de/de/security/2002_024_openssh_txt.html
https://rhn.redhat.com/errata/RHSA-2002-127.html
https://rhn.redhat.com/errata/RHSA-2002-131.html

Tools & Filters

	11031 12309 14971
	1987

Credit

Unknown or Incomplete

CVSSv2 Score

CVSSv2 Base Score = 10.0
Source: nvd.nist.gov | Generated: 2003-12-31 | Disagree?

Blogs

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