CVE-2013-3660
HIGHThe EPATHOBJ::pprFlattenRec function in win32k.sys in the kernel-mode drivers in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2…
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
The EPATHOBJ::pprFlattenRec function in win32k.sys in the kernel-mode drivers in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, and Windows Server 2012 does not properly initialize a pointer for the next object in a certain list, which allows local users to obtain write access to the PATHRECORD chain, and consequently gain privileges, by triggering excessive consumption of paged memory and then making many FlattenPath function calls, aka "Win32k Read AV Vulnerability."
Affected Products
windows 7microsoftwindows 8microsoftwindows rtmicrosoftwindows server 2003microsoftwindows server 2008microsoftwindows server 2012microsoftResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Microsoft Windows NT/2000/2003/2008/XP/Vista/7/8 - 'EPATHOBJ' Local Ring
by Tavis Ormandy · Jun 3, 2013
Microsoft Windows - Win32k!EPATHOBJ::pprFlattenRec Uninitialized Next Pointer Testcase
by Tavis Ormandy · May 21, 2013
Microsoft Windows - 'EPATHOBJ::pprFlattenRec' Local Privilege Escalation (Metasploit)
by Metasploit · Jul 2, 2013
Detection & mitigation playbook
Vendor / applianceDetect
Inventory every microsoft windows 7 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-2013-3660 yet — track the microsoft windows 7 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-2013-3660 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-2013-3660. 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-2013-3660 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2013-3660 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.