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Mallory
High

GnuTLS certtool template parsing heap-buffer overflow (off-by-one)

IdentifiersCVE-2025-32990CWE-193

CVE-2025-32990 is a heap-based buffer overflow in GnuTLS affecting the template parsing logic of the certtool utility. According to the provided content, when certtool reads certain settings from a template file, an off-by-one condition leads to an out-of-bounds NULL pointer write on the heap. This memory corruption condition occurs during parsing of attacker-controlled or malformed template input and can cause the process to crash. The issue is described as residing specifically in certtool's template parsing path rather than the core TLS protocol handling path.

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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 corrupt heap memory in the certtool process and trigger a denial of service by crashing the utility. Based on the provided information, the demonstrated impact is process instability and DoS due to an out-of-bounds NULL write. The content does not provide verified evidence of reliable code execution, so the confirmed impact should be limited to memory corruption and crash/DoS.

Mitigation

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

Until patched, avoid processing untrusted or externally supplied certtool template files, restrict access to systems and workflows that invoke certtool with template input, and limit use of vulnerable automation paths that parse attacker-influenced certificate templates. In downstream products, reduce exposure by applying vendor-recommended temporary controls and restricting access to affected components, but patching is the primary mitigation.

Remediation

Patch, then assume compromise.

Apply vendor-provided fixes for CVE-2025-32990 in GnuTLS and update any downstream products that bundle the vulnerable GnuTLS component, such as affected Oracle Communications and VMware Tanzu distributions referenced in the content. Where applicable, install the relevant Oracle Critical Patch Update or the fixed Tanzu release/stemcell/package versions identified by the vendor advisories. If running unsupported versions, upgrade to a supported release that includes the fix.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
GNU ProjectGnutlsapplication
Red HatEnterprise Linuxoperating_system
Red HatOpenshift Container Platformapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

9 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

What this page doesn’t show

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Exposure mapping

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Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity6

Community discussion across Reddit, Mastodon, and other social sources.