CVE-2011-0539
The key_certify function in usr.bin/ssh/key.c in OpenSSH 5.6 and 5.7, when generating legacy...
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.
Exploit likelihood
What each source reports
CVE List
7.5
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.
- Record
CVE-2011-0539- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-457
- Updated
- 2026-11-02
EUVDEUVD-2011-0557
7.5
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.
- Record
EUVD-2011-0557- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-395x-3x8q-mv38
7.5
The key_certify function in usr.bin/ssh/key.c in OpenSSH 5.6 and 5.7, when generating legacy...
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.
- Record
GHSA-395x-3x8q-mv38- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-457
- Updated
- 2026-11-02
NVD
7.5
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.
- Record
CVE-2011-0539- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:P/I:N/A:N - Weakness
- CWE-264, CWE-457
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2011-0539
7.5
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.
- Record
DEBIAN-CVE-2011-0539- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSV No score
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.
- Record
CVE-2011-0539- Updated
- 2026-11-02
Affected products
Affected packages
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2011-0539 is a medium vulnerability (CVSS 5.0) in Openbsd Openssh, published February 10, 2011. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.85%, the 79th percentile. Fixed in openssh 1:5.8p1-2.
References
openwall.com/lists/oss-security/2011/02/04/2
securitytracker.com/id?1025028
securityfocus.com/bid/46155
kb.juniper.net/InfoCenter/index?page=content&id=JSA10673
vupen.com/english/advisories/2011/0284
secunia.com/advisories/43181
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h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c02794777
secunia.com/advisories/44269
openssh.com/txt/legacy-cert.adv
exchange.xforce.ibmcloud.com/vulnerabilities/65163
nvd.nist.gov/vuln/detail/CVE-2011-0539
github.com/advisories/GHSA-395x-3x8q-mv38
security-tracker.debian.org/tracker/CVE-2011-0539