There's a vulnerability in the libssh package where when a libssh consumer passes in an unexpectedly large input buffer…
Summary
Out-of-bounds write reported (CVE-2025-4877). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
There's a vulnerability in the libssh package where when a libssh consumer passes in an unexpectedly large input buffer to ssh_get_fingerprint_hash() function. In such cases the bin_to_base64() function can experience an integer overflow leading to a memory under allocation, when that happens it's possible that the program perform out of bounds write leading to a heap corruption.
This issue affects only 32-bits builds of libssh.
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-2025-4877 has been found.
Risk of unauthorized operations or information disclosure. CVSS score: 4.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "CVE-2025-4877" on the vendor's site.
CVE-2025-4877 — CWE-787 / CVSS v3 4.5
Attack vector: local / 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.
Out-of-bounds write (CWE-787) has been reported.
Check the vendor advisory for the affected versions.
Severity: Medium (CVSS 4.5/10). 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
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで影響コンポーネントを特定する。
-
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-2025-4877 libssh Fixed in: 0.9.8-0+deb11u2
References
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web nvd.nist.gov
- web github.com