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Mallory
Medium

Heap buffer over-read in GnuTLS SCT extension parsing

IdentifiersCVE-2025-32989CWE-125

CVE-2025-32989 is a heap-buffer-overread vulnerability in GnuTLS during X.509 certificate parsing. The flaw occurs in handling of the Certificate Transparency (CT) Signed Certificate Timestamp (SCT) extension, identified by OID 1.3.6.1.4.1.11129.2.4.2. A maliciously crafted certificate containing a malformed SCT extension can trigger out-of-bounds reads from heap memory when GnuTLS parses and verifies certificates. According to the provided description, this can expose sensitive data because the SCT content is not checked correctly during certificate verification for certain websites.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation can cause disclosure of confidential information from process heap memory during certificate verification. The primary impact described in the provided content is information exposure rather than code execution or integrity compromise. An attacker able to present a malicious certificate to a GnuTLS-using client or service may cause the vulnerable process to over-read heap memory and leak sensitive data associated with that process.

Mitigation

If you can’t patch tonight, do this now.

Until patched packages are deployed, reduce exposure by avoiding trust decisions on untrusted or attacker-supplied certificates where possible and limiting connections to endpoints that could present malicious X.509 certificate chains. If feasible, use updated downstream packages from platform vendors and restrict affected applications' exposure to hostile TLS endpoints. No specific workaround beyond patching is provided in the supplied content.

Remediation

Patch, then assume compromise.

Apply the vendor patch for GnuTLS that fixes SCT extension parsing for CVE-2025-32989. The provided content indicates that the patch for CVE-2025-32990 also addresses CVE-2025-32989. Where this issue is inherited through downstream products or distributions, install the corresponding updated package from the vendor or distribution maintainer.
PUBLIC EXPLOITS

Exploits

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VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

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VendorProductType
GNU ProjectGnutlsapplication
Red HatEnterprise Linuxoperating_system
Red HatOpenshift Container Platformapplication

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What this page doesn’t show

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Threat actor evidence

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Associated malware

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Detection signatures

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Vendor-by-vendor mapping

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Social activity2

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