Vulnerability in OpenSSH server (CVE-2023-25136)
Summary
Vulnerability in OpenSSH server (CVE-2023-25136). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
OpenSSH server (sshd) 9.1 introduced a double-free vulnerability during options.kex_algorithms handling. This is fixed in OpenSSH 9.2. The double free can be triggered by an unauthenticated attacker in the default configuration; however, the vulnerability discoverer reports that "exploiting this vulnerability will not be easy."
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2023-25136 has been found in OpenSSH server.
Risk of unauthorized operations or information disclosure. CVSS score: 6.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "OpenSSH server CVE-2023-25136" on the vendor's site.
CVE-2023-25136 (OpenSSH server) — CWE-415 / CVSS v3 6.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-415) exists in OpenSSH server.
Check the vendor advisory for the affected versions of OpenSSH server.
Severity: Medium (CVSS 6.5/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで OpenSSH server を使っているサービスとバージョンを洗い出す。
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2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2023-25136 openssh Fixed in: 1:9.2p1-1
References
- advisory openwall.com
- advisory openwall.com
- advisory openwall.com
- advisory openwall.com
- advisory openwall.com
- advisory openwall.com
- advisory news.ycombinator.com
- advisory security.gentoo.org
- advisory security.netapp.com
- exploit bugzilla.mindrot.org
- exploit jfrog.com
- exploit openwall.com
- patch ftp.openbsd.org
- patch github.com
- web lists.fedoraproject.org
- web lists.fedoraproject.org
- web nvd.nist.gov
- web jfrog.com
- web lists.fedoraproject.org
- web lists.fedoraproject.org
- web lists.fedoraproject.org
- web lists.fedoraproject.org
- web security.netapp.com
- web cert-portal.siemens.com
- web github.com