CVE-2010-3765
CRITICALMozilla 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…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Description
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 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.
Affected Products
firefoxmozillaseamonkeymozillathunderbirdmozillaResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Mozilla Firefox 3.6.8 < 3.6.11 - Interleaving 'document.write' / 'appendChild' Remote Overflow
by anonymous · Oct 29, 2010
Mozilla Firefox - Interleaving 'document.write' / 'appendChild' (Metasploit)
by Metasploit · Feb 22, 2011
Mozilla Firefox - Interleaving 'document.write' / 'appendChild' Denial of Service
by Daniel Veditz · Oct 28, 2010
Mozilla Firefox - Simplified Memory Corruption (PoC)
by extraexploit · Oct 28, 2010
Detection & mitigation playbook
Vendor / applianceDetect
Inventory every mozilla firefox deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Remediation status
No patch has shipped for CVE-2010-3765 yet — track the mozilla firefox advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2010-3765 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2010-3765. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2010-3765 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2010-3765 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.