CVE-2023-6918: Libssh: missing checks for return values for digests
First published: Mon Dec 18 2023(Updated: )
A flaw was found in the libssh implements abstract layer for message digest (MD) operations implemented by different supported crypto backends. The return values from these were not properly checked, which could cause low-memory situations failures, NULL dereferences, crashes, or usage of the uninitialized memory as an input for the KDF. In this case, non-matching keys will result in decryption/integrity failures, terminating the connection.
Credit: secalert@redhat.com secalert@redhat.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| debian/libssh | 0.9.8-0+deb11u1 0.10.6-0+deb12u1 0.11.1-1 | |
| redhat/libssh | <0.9.8 | 0.9.8 |
| redhat/libssh | <0.10.6 | 0.10.6 |
| Ubuntu | >=0.9.0<0.9.8 | |
| Ubuntu | >=0.10.0<0.10.6 | |
| Fedora | =38 | |
| Fedora | =39 | |
| Red Hat Enterprise Linux | =8.0 | |
| Red Hat Enterprise Linux | =9.0 | |
| IBM MQ | <=CD: v3.0.0, v3.0.1, v3.1.0 - 3.1.3 LTS: v2.0.0 - 2.0.22 Other Release: v2.4.0 - v2.4.8, v2.3.0 - 2.3.3, v2.2.0 - v2.2.2 | |
| IBM MQ Advanced | <=CD: 9.3.4.0-r1, 9.3.4.1-r1,9.3.5.0-r1,9.3.5.0-r2,9.3.5.1-r1, 9.3.5.1-r2LTS: 9.2.0.1-r1-eus, 9.2.0.2-r1-eus, 9.2.0.2-r2-eus, 9.2.0.4-r1-eus, 9.2.0.5-r1-eus, 9.2.0.5-r2-eus, 9.2.0.5-r3-eus, 9.2.0.6-r1-eus, 9.2.0.6-r2-eus, 9.2.0.6-r3-eus, 9.2.3.0-r1, 9.2.4.0-r1, 9.2.5.0-r1, 9.2.5.0-r2, 9.2.5.0-r3, 9.3.0.0-r1, 9.3.0.0-r2, 9.3.0.0-r3, 9.3.0.1-r1, 9.3.0.1-r2, 9.3.0.1-r3, 9.3.0.1-r4, 9.3.0.3-r1, 9.3.0.4-r1, 9.3.0.4-r2, 9.3.0.5-r1, 9.3.0.5-r2, 9.3.0.5-r3, 9.3.0.6-r1, 9.3.0.10-r1, 9.3.0.10-r2, 9.3.0.11-r1,9.3.0.11-r2, 9.3.0.15-r1, 9.3.0.16-r1, 9.3.0.16-r2, 9.3.0.17-r1, 9.3.0.17-r2 Other Release: 9.2.0.1-r1-eus, 9.2.0.2-r1-eus, 9.2.0.2-r2-eus, 9.2.0.4-r1-eus, 9.2.0.5-r1-eus, 9.2.0.5-r2-eus, 9.2.0.5-r3-eus, 9.2.0.6-r1-eus, 9.2.0.6-r2-eus, 9.2.0.6-r3-eus, 9.2.3.0-r1, 9.2.4.0-r1, 9.2.5.0-r1, 9.2.5.0-r2, 9.2.5.0-r3, 9.3.0.0-r1, 9.3.0.0-r2, 9.3.0.0-r3, 9.3.0.1-r1, 9.3.0.1-r2, 9.3.0.1-r3, 9.3.0.1-r4, 9.3.0.3-r1, 9.3.0.4-r1, 9.3.0.4-r2, 9.3.0.5-r1, 9.3.0.5-r2, 9.3.0.5-r3, 9.3.0.6-r1, 9.3.1.0-r1, 9.3.1.0-r2, 9.3.1.0-r3, 9.3.1.1-r1, 9.3.2.0-r1, 9.3.2.0-r2, 9.3.2.1-r1, 9.3.2.1-r2, 9.3.3.0-r1, 9.3.3.0-r2, 9.3.3.1-r1, 9.3.3.1-r2, 9.3.3.2-r1, 9.3.3.2-r2, 9.3.3.2-r3, ,9.3.3.3-r1, 9.3.3.3-r2 | |
| libssh | >=0.9.0<0.9.8 | |
| libssh | >=0.10.0<0.10.6 |
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Reference Links
- https://bugzilla.redhat.com/show_bug.cgi?id=2254997
- https://access.redhat.com/security/cve/CVE-2023-6918
- https://www.libssh.org/2023/12/18/libssh-0-10-6-and-libssh-0-9-8-security-releases/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MKQRBF3DWMWPH36LBCOBUTSIZRTPEZXB/
- https://www.libssh.org/security/advisories/CVE-2023-6918.txt
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/LZQVUHWVWRH73YBXUQJOD6CKHDQBU3DM/
- https://access.redhat.com/errata/RHSA-2024:2504
- https://access.redhat.com/errata/RHSA-2024:3233
- https://launchpad.net/bugs/cve/CVE-2023-6918
- https://gitlab.com/libssh/libssh-mirror/-/commit/610d7a09f99c601224ae2aa3d3de7e75b1d284dd
- https://gitlab.com/libssh/libssh-mirror/-/commit/63ff242131c8e6d98917456f71f6d33b9ef3a763
- https://gitlab.com/libssh/libssh-mirror/-/commit/8b66d037d575e5f3ce4d35964547ff8c7e75ff8e
- https://gitlab.com/libssh/libssh-mirror/-/commit/8977e246b6d7ae467cab008a49e0a9e3d84bc2a0
- https://gitlab.com/libssh/libssh-mirror/-/commit/622421018b58392ffecc29726b947e089b678221
- https://security-tracker.debian.org/tracker/CVE-2023-6918
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-6918
- https://nvd.nist.gov/vuln/detail/CVE-2023-6918
- https://ubuntu.com/security/CVE-2023-6918
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2255157
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2255159
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2255158
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2255160
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2255161
- https://exchange.xforce.ibmcloud.com/vulnerabilities/275423
- https://www.ibm.com/support/pages/node/7157667 (Advisory)
- https://security.netapp.com/advisory/ntap-20250214-0009/
Frequently Asked Questions
What is the severity of CVE-2023-6918?
CVE-2023-6918 has a high severity rating due to potential denial of service risks from unhandled return values.
How do I fix CVE-2023-6918?
To fix CVE-2023-6918, update libssh to the latest versions specifically 0.9.8-0+deb11u1, 0.10.6-0+deb12u1, or 0.11.1-1.
What software is affected by CVE-2023-6918?
CVE-2023-6918 affects libssh versions below 0.10.6, various IBM MQ Operator releases, and specific versions of Red Hat and Debian distributions.
What can happen if CVE-2023-6918 is exploited?
Exploitation of CVE-2023-6918 can lead to low memory situations, program crashes, and potential application downtime.
Is my version of libssh vulnerable to CVE-2023-6918?
If you are running libssh versions prior to 0.10.6 or within the affected ranges listed, your version is vulnerable to CVE-2023-6918.
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- canonical/libssh
- version/libssh/0.9.0
- version/libssh/0.10.0