CVE-2015-6564

Advisory lineage Upstream: 0 Downstream: 8
Modified
Published: 24 Aug 2015, 00:00
Last modified:27 May 2026, 16:18

Vulnerability Summary

Overall Risk (default)
medium
29/100
CVSS Score
7 HIGH
v3.1 (nvd)
EPSS Score
4.03% LOW
4% probability +1.96%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

24 Aug 2015, 00:00
Published
Vulnerability first disclosed
27 May 2026, 16:18
Last Modified
Vulnerability information updated

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.

CVSS Metrics

  • v3.1•HIGH•Score: 7CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
  • v2.0•MEDIUM•Score: 6.9AV:L/AC:M/Au:N/C:C/I:C/A:C

EPSS Trends

Current EPSS score: 4.03%• Percentile: 89%

Techniques & Countermeasures

  • CWE-264•Permissions, Privileges, and Access Controls

    Weaknesses in this category are related to the management of permissions, privileges, and other security features that are used to perform access control.

  • CWE-416•Use After Free

    The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

  • openbsd•openssh

    ≤ 6.9

References (16)