openssh: Use-after-free bug related to PAM support
Published Aug 24, 2015
7.0
HIGHCVSS 3.1
EPSS 0.60%
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
No data.
No data.
Red Hat Enterprise Linux 6
openssh-0:5.3p1-117.el6
Fixed · RHSA-2016:0741
Red Hat Enterprise Linux 7
openssh-0:6.6.1p1-22.el7
Fixed · RHSA-2015:2088
Red Hat Enterprise Linux 4
openssh
Will not fix
Red Hat Enterprise Linux 5
openssh
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 6 | openssh-0:5.3p1-117.el6 | Fixed | RHSA-2016:0741 |
| Red Hat Enterprise Linux 7 | openssh-0:6.6.1p1-22.el7 | Fixed | RHSA-2015:2088 |
| Red Hat Enterprise Linux 4 | openssh | Will not fix | n/a |
| Red Hat Enterprise Linux 5 | openssh | Will not fix | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
No CVSS v3.0 score for this CVE.
AV:L/AC:M/Au:N/C:C/I:C/A:C
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
NoTechnical Impact
TotalDecision
n/aAssessed May 27, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (18 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.60% (0.00604) | 46.99th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.60% (0.00604) | 44.07th | v5 (v2026.06.15) |
| May 28, 2026 | 4.03% (0.04032) | 88.67th | v4 (v2025.03.14) |
| Oct 28, 2025 | 3.00% (0.02995) | 86.04th | v4 (v2025.03.14) |
| Oct 27, 2025 | 4.75% (0.04746) | 88.96th | v4 (v2025.03.14) |
| Oct 1, 2025 | 3.00% (0.02995) | 86.10th | v4 (v2025.03.14) |
| Aug 19, 2025 | 4.75% (0.04746) | 88.99th | v4 (v2025.03.14) |
| Jul 30, 2025 | 3.62% (0.03621) | 87.36th | v4 (v2025.03.14) |
| Mar 30, 2025 | 2.27% (0.02272) | 83.17th | v4 (v2025.03.14) |
| Mar 29, 2025 | 4.14% (0.04144) | 80.76th | v4 (v2025.03.14) |
| Mar 17, 2025 | 2.27% (0.02272) | 83.49th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.04% (0.00044) | 11.89th | v3 (v2023.03.01) |
| Jul 2, 2024 | 0.04% (0.00044) | 10.25th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.04% (0.00044) | 8.24th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.55% (0.01547) | 74.98th | v2 (v2022.01.01) |
| Feb 23, 2023 | 1.55% (0.01547) | 74.94th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.55% (0.01547) | 72.92th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.55% (0.01547) | 51.82th | v2 (v2022.01.01) |
References (20)
- http://lists.fedoraproject.org/pipermail/package-announce/2015-August/165170.html vendor-advisory
- http://lists.opensuse.org/opensuse-security-announce/2015-09/msg00017.html vendor-advisory
- http://rhn.redhat.com/errata/RHSA-2016-0741.html vendor-advisory
- http://seclists.org/fulldisclosure/2015/Aug/54 mailing-list
- http://www.openssh.com/txt/release-7.0 Vendor Advisory
- http://www.openwall.com/lists/oss-security/2015/08/22/1 mailing-list
- 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 vdb-entry
- https://access.redhat.com/security/cve/CVE-2015-6564 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1252852 Issue Tracking
- https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf
- https://github.com/openssh/openssh-portable/commit/5e75f5198769056089fb06c4d738ab0e5abc66f7
- https://kc.mcafee.com/corporate/index?page=content&id=SB10136
- https://lists.debian.org/debian-lts-announce/2018/09/msg00010.html mailing-list
- https://nvd.nist.gov/vuln/detail/CVE-2015-6564
- https://security.gentoo.org/glsa/201512-04 vendor-advisory
- https://www.broadcom.com/support/fibre-channel-networking/security-advisories/brocade-security-advisory-2019-764
- https://www.cve.org/CVERecord?id=CVE-2015-6564
Change history (0)
No recorded changes yet.