Vulnerability in libssh2 (CVE-2019-3863)
Summary
Vulnerability in libssh2 (CVE-2019-3863). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
A flaw was found in libssh2 before 1.8.1. A server could send a multiple keyboard interactive response messages whose total length are greater than unsigned char max characters. This value is used as an index to copy memory causing in an out of bounds memory write error.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
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-2019-3863 has been found in libssh2.
Successful exploitation can lead to full system takeover. CVSS score: 7.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "libssh2 CVE-2019-3863" on the vendor's site.
CVE-2019-3863 (libssh2) — CWE-190 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated
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-190) exists in libssh2.
Check the vendor advisory for the affected versions of libssh2.
Severity: High (CVSS 7.5/10). Successful exploitation can lead to full system takeover.
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. Run grep -r 'libssh2' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'libssh2' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
libssh2を grep し、稼働しているサービス・バージョンを把握する。 -
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
- Alpine Linux ALPINE-CVE-2019-3863 libssh2 Fixed in: 1.8.1-r0
References
- advisory security.netapp.com
- web lists.fedoraproject.org
- web seclists.org
- web lists.opensuse.org
- web lists.opensuse.org
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web lists.debian.org
- web debian.org
- web oracle.com
- web bugzilla.redhat.com
- web libssh2.org
- web cert-portal.siemens.com
- web nvd.nist.gov
- web lists.fedoraproject.org
- web lists.fedoraproject.org
- web security.netapp.com
- web github.com