CVE-2011-0539: openbsd openssh
CVSS: 7.5v3.1HighModified
AliasesDEBIAN-CVE-2011-0539
Published 10-02-2011Last modified 29-05-2026
Vulnerability summary
CVE-2011-0539 is a high (CVSS 7.5) vulnerability in openbsd openssh. EPSS estimates a 1.81% chance of exploitation in the next 30 days, higher than 78.3% of scored vulnerabilities.
CVSS score
7.5/10
010
High · v3.1 (CVE.org)EPSS score
1.81%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 10-02-2011PublishedVulnerability first disclosed.
- 29-05-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
4 scores · 3 sources · 2 versionsHigh 7.5Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NSourcesAll 3 agree
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Medium 5.0Preferred score · NVD (NIST)
AV:N/AC:L/Au:N/C:P/I:N/A:NSourcesSingle source
EPSS trend
Probability
1.81%
Chance of exploitation in the next 30 days
Percentile
78%
Versus all other CVEs
30-day change
0.00 pp
From 1.81% on 20-09-2026
20-09-202620-10-2026
EPSS score1.81%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-264Permissions, Privileges, and Access ControlsWeaknesses in this category are related to the management of permissions, privileges, and other security features that are used to perform access control.
- CWE-457Use of Uninitialized VariableThe code uses a variable that has not been initialized, leading to unpredictable or unintended results.
Affected systems
Debian1 product
- openssh< 1:5.8p1-2
Openbsd1 product
- openssh5.6 | 5.7
2 vendors · 2 products
References
11 links- kb.juniper.net/InfoCenter/index?page=content&id=JSA10673X Refsource CONFIRM
- h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c02794777Vendor AdvisoryX Refsource HP
