Security Resilience

CVE-2010-3765

Memory Safety in Mozilla Firefox 3.5 … 3.6.9

CISA KEVActive ExploitationEUVD ExploitedPublic PoCMemory Safety
Published
28 October 2010
Modified
22 April 2026
KEV Added
06 October 2025
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.83 99.7th percentile
Risk Priority 97 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2010-3765 is a critical-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Mozilla Firefox. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 0.3% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability Data

Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before 3.1.6 and 3.0.x before 3.0.10, and SeaMonkey 2.x before 2.0.10, when JavaScript is enabled, allows remote attackers to execute arbitrary code via vectors related to nsCSSFrameConstructor::ContentAppended, the appendChild…

more

method, incorrect index tracking, and the creation of multiple frames, which triggers memory corruption, as exploited in the wild in October 2010 by the Belmoo malware.

CWE(s)
KEV Date Added
06 October 2025

Related Threats

Threat-Actor AttributionAI

Belmoo
CVE-2010-3765 was exploited in the wild in October 2010 by Belmoo malware, as documented in NVD/Mozilla advisories and contemporary reporting.

CVEs Like This One

CVE-2026-8974Same product: Mozilla Firefox
CVE-2025-9184Same product: Mozilla Firefox
CVE-2025-6436Same product: Mozilla Firefox
CVE-2025-9185Same product: Mozilla Firefox
CVE-2026-2779Same product: Mozilla Firefox
CVE-2025-4093Same product: Mozilla Firefox
CVE-2026-100764Same product: Mozilla Firefox
CVE-2026-92048Same product: Mozilla Firefox
CVE-2026-100781Same product: Mozilla Firefox
CVE-2026-8954Same product: Mozilla Firefox

Affected Assets

mozilla
firefox
3.5, 3.5.1, 3.5.10, 3.5.11, 3.5.12
mozilla
thunderbird
3.0.1, 3.0.2, 3.0.3, 3.0.4, 3.0.5
mozilla
seamonkey
2.0, 2.0.1, 2.0.2, 2.0.3, 2.0.4

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-119

Ongoing control assessments and code testing (static/dynamic analysis, fuzzing) surface memory buffer restriction failures, which are then remediated before release.

addresses: CWE-119

Managed runtimes used by platform-independent applications (e.g., JVM, CLR) enforce memory safety, preventing most buffer overflows that require direct memory manipulation.

addresses: CWE-119

Memory protections (e.g., W^X, ASLR) make exploitation of buffer-boundary violations far harder to turn into code execution.

addresses: CWE-119

Detects exploitation attempts that produce memory corruption, crashes, or anomalous behavior.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

blocks

A.8.25 mandates secure SDLC practices (secure coding guidelines, security requirements, testing including code scans and penetration tests, developer training) that reach buffer management and can stop many buffer overruns from reaching production, but leaves a bounded remainder (e.g. flaws in non-software components, incomplete enforcement of guidelines, or post-deployment changes)

blocks

Application security requirements can specify memory-safety rules, but do not prescribe implementation details.

blocks

A.8.27 mandates security-by-design principles (e.g. least privilege, fail securely, distrust external input, hardening) plus design reviews that can catch and stop buffer-boundary errors before they reach code, but this is only one minority slice of CWE-119's broad surface (language-specific flaws, unsafe library use, compiler/runtime mitigations, and post-deployment instances remain outside its direct scope).

prevents

Secure coding standards explicitly forbid unsafe buffer operations, directly eliminating CWE-119.

finds

Security testing in development catches out-of-bounds accesses before release, covering most instances of the weakness.

Hardening callouts derived

DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.

  • No fine-grained STIG row for CWE-119, a class-level weakness. Rules are authored against its narrower children: CWE-823.

References