Vulnerability in GnuTLS library (CVE-2025-9820)
Summary
Vulnerability in GnuTLS library (CVE-2025-9820). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
A flaw was found in the GnuTLS library, specifically in the gnutls_pkcs11_token_init() function that handles PKCS#11 token initialization. When a token label longer than expected is processed, the function writes past the end of a fixed-size stack buffer. This programming error can cause the application using GnuTLS to crash or, in certain conditions, be exploited for code execution. As a result, systems or applications relying on GnuTLS may be vulnerable to a denial of service or local privilege escalation attacks.
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-2025-9820 has been found in GnuTLS library.
Risk of unauthorized operations or information disclosure. CVSS score: 4.0/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "GnuTLS library CVE-2025-9820" on the vendor's site.
CVE-2025-9820 (GnuTLS library) — CWE-121 / CVSS v3 4.0
Attack vector: local / 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-121) exists in GnuTLS library.
Check the vendor advisory for the affected versions of GnuTLS library.
Severity: Medium (CVSS 4.0/10). 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 GnuTLS library 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
- Alpine Linux ALPINE-CVE-2025-9820 gnutls Fixed in: 3.8.12-r0
- Debian DEBIAN-CVE-2025-9820 gnutls28 Fixed in: 3.7.1-5+deb11u9
- Ubuntu UBUNTU-CVE-2025-9820 gnutls28 Fixed in: 3.4.10-4ubuntu1.9+esm3
References
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web openwall.com
- web cert-portal.siemens.com
- web nvd.nist.gov
- web github.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com