CVE-2011-0539

Severity: medium (CVSS 5.0 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2011-02-10 · updated 2026-06-16
Weakness: CWE-264

Description

The key_certify function in usr.bin/ssh/key.c in OpenSSH 5.6 and 5.7, when generating legacy certificates using the -t command-line option in ssh-keygen, does not initialize the nonce field, which might allow remote attackers to obtain sensitive stack memory contents or make it easier to conduct hash collision attacks.

Affected products

OpenSSH: 5.6, 5.7

References

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c02794777
http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10673
http://secunia.com/advisories/43181
http://secunia.com/advisories/44269
http://www.openssh.com/txt/legacy-cert.adv
http://www.openwall.com/lists/oss-security/2011/02/04/2
http://www.securityfocus.com/bid/46155
http://www.securitytracker.com/id?1025028
http://www.vupen.com/english/advisories/2011/0284
https://exchange.xforce.ibmcloud.com/vulnerabilities/65163
http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c02794777
http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10673

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