CVE-2015-6564

Severity: medium (CVSS 6.9 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2015-08-24 · updated 2026-06-17
Weakness: CWE-264

Description

Use-after-free vulnerability in the mm_answer_pam_free_ctx function in monitor.c in sshd in OpenSSH before 7.0 on non-OpenBSD platforms might allow local users to gain privileges by leveraging control of the sshd uid to send an unexpectedly early MONITOR_REQ_PAM_FREE_CTX request.

Affected products

OpenSSH: through 6.9

References

http://lists.fedoraproject.org/pipermail/package-announce/2015-August/165170.html
http://lists.opensuse.org/opensuse-security-announce/2015-09/msg00017.html
http://rhn.redhat.com/errata/RHSA-2016-0741.html
http://seclists.org/fulldisclosure/2015/Aug/54
http://www.openssh.com/txt/release-7.0
http://www.openwall.com/lists/oss-security/2015/08/22/1
http://www.oracle.com/technetwork/topics/security/bulletinjan2016-2867206.html
http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html
http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html
http://www.securityfocus.com/bid/76317
https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf
https://github.com/openssh/openssh-portable/commit/5e75f5198769056089fb06c4d738ab0e5abc66f7

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