Description
The shared memory manager (associated with pre-authentication compression) in sshd in OpenSSH before 7.4 does not ensure that a bounds check is enforced by all compilers, which might allows local users to gain privileges by leveraging access to a sandboxed privilege-separation process, related to the m_zback and m_zlib data structures.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | openssh | 1:7.4p1-1 | — |
| Debian 13 | openssh | 1:7.4p1-1 | — |
| Debian 12 | openssh | 1:7.4p1-1 | — |
| Debian 8 | openssh | 1:6.7p1-5+deb8u6 | DLA-1500-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | openssh | 1:7.2p2-4ubuntu2.4 | USN-3538-1 |
| Ubuntu 14.04 LTS | openssh | 1:6.6p1-2ubuntu2.10 | USN-3538-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | openssh +7 | 7.4p1-11.el7 | RHSA-2017:2029 |
| RHEL 7 | pam_ssh_agent_auth | 0.10.3-1.11.el7 | RHSA-2017:2029 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | openssh | 7.2p2-66.1 | SUSE-SU-2017:0264-1 |
| SLES 12 SP2 | openssh-askpass-gnome | 7.2p2-66.3 | SUSE-SU-2017:0264-1 |
| SLES 12 SP1 | openssh | 6.6p1-54.15.2 | SUSE-SU-2018:2685-1 |
| SLES 12 SP1 | openssh-askpass-gnome | 6.6p1-54.15.1 | SUSE-SU-2018:2685-1 |
| SLES 12 | openssh | 6.6p1-54.15.2 | SUSE-SU-2018:2685-1 |
| SLES 12 | openssh-askpass-gnome | 6.6p1-54.15.1 | SUSE-SU-2018:2685-1 |
| SLES 11 SP4 | openssh +1 | 6.6p1-36.3.1 | SUSE-SU-2018:2275-1 |
| SLES 11 SP3 | openssh +1 | 6.2p2-0.41.5.1 | SUSE-SU-2018:3540-1 |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 11 | openssh-openssl1 | 6.6p1-19.3.1 | SUSE-SU-2018:2719-1 |
| SLES for SAP 12 SP2 | openssh | 7.2p2-66.1 | SUSE-SU-2017:0264-1 |
| SLES for SAP 12 SP2 | openssh-askpass-gnome | 7.2p2-66.3 | SUSE-SU-2017:0264-1 |
| SLES for SAP 12 SP1 | openssh | 6.6p1-54.15.2 | SUSE-SU-2018:2685-1 |
| SLES for SAP 12 SP1 | openssh-askpass-gnome | 6.6p1-54.15.1 | SUSE-SU-2018:2685-1 |
| SLES for SAP 11 SP4 | openssh +1 | 6.6p1-36.3.1 | SUSE-SU-2018:2275-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | openssh +1 | 6.2p2-0.41.5.1 | SUSE-SU-2018:3540-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | openssh | 8.4p1-7.4 | openSUSE-SU-2024:11124-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | openssh | 7.4_p1-r0 | — |
| Alpine v3.23 | openssh | 7.4_p1-r0 | — |
| Alpine v3.22 | openssh | 7.4_p1-r0 | — |
| Alpine v3.21 | openssh | 7.4_p1-r0 | — |
| Alpine v3.20 | openssh | 7.4_p1-r0 | — |
Show 17 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | openssh | 7.4_p1-r0 | — |
| Alpine v3.18 | openssh | 7.4_p1-r0 | — |
| Alpine v3.17 | openssh | 7.4_p1-r0 | — |
| Alpine v3.16 | openssh | 7.4_p1-r0 | — |
| Alpine v3.15 | openssh | 7.4_p1-r0 | — |
| Alpine v3.14 | openssh | 7.4_p1-r0 | — |
| Alpine v3.13 | openssh | 7.4_p1-r0 | — |
| Alpine v3.12 | openssh | 7.4_p1-r0 | — |
| Alpine v3.11 | openssh | 7.4_p1-r0 | — |
| Alpine v3.10 | openssh | 7.4_p1-r0 | — |
| Alpine v3.9 | openssh | 7.4_p1-r0 | — |
| Alpine v3.8 | openssh | 7.4_p1-r0 | — |
| Alpine v3.7 | openssh | 7.5_p1-r8 | — |
| Alpine v3.6 | openssh | 7.4_p1-r0 | — |
| Alpine v3.5 | openssh | 7.4_p1-r0 | — |
| Alpine v3.4 | openssh | 7.2_p2-r4 | — |
| Alpine v3.3 | openssh | 7.2_p2-r3 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | openssh +7 | 7.4p1-11.el7 | ELSA-2017-2029 |
| Oracle Linux 7 | pam_ssh_agent_auth | 0.10.3-1.11.el7 | ELSA-2017-2029 |
Advisories 13
- RHSA-2017:2029 Red Hat Security Advisory: openssh security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-3538-1 openssh vulnerabilities Ubuntu Security Notices (USN) · Jun 1, 2026
- DLA-1500-1 openssh - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2018:2719-1 Security update for openssh-openssl1 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:0264-1 Security update for openssh SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:2275-1 Security update for openssh SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:3540-1 Security update for openssh SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:11124-1 openssh-8.4p1-7.4 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2023-1996 OpenSSH: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jan 12, 2026
- SUSE-SU-2018:2685-1 Security update for openssh SUSE / openSUSE Security Updates · May 2, 2025
- ICSA-22-349-21 Siemens SCALANCE X-200RNA Switch Devices CISA ICS & IT advisories · Dec 13, 2022
- SSA-412672 SSA-412672: Multiple OpenSSL and OpenSSH Vulnerabilities in SCALANCE X-200RNA Switch Devices before V3.2.7 Siemens ProductCERT · Dec 13, 2022
- ELSA-2017-2029 Moderate: openssh security, bug fix, and enhancement update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Aug 7, 2017
References
- https://security.netapp.com/advisory/ntap-20171130-0002/
- [oss-security] 20161219 Announce: OpenSSH 7.4 released mailing-list
- 1037490 vdb-entry
- https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03818en_us
- http://www.slackware.com/security/viewer.php?l=slackware-security&y=2016&m=slackware-security.647637
- RHSA-2017:2029 vendor-advisory
- [debian-lts-announce] 20180910 [SECURITY] [DLA 1500-1] openssh security update mailing-list
- https://www.openssh.com/txt/release-7.4
- 94975 vdb-entry
- https://github.com/openbsd/src/commit/3095060f479b86288e31c79ecbc5131a66bcd2f9
- https://support.f5.com/csp/article/K62201745?utm_source=f5support&%3Butm_medium=RSS
- https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf