CVE-2012-1876: Internet Explorer memory object handling remote code execution

Automated analysis

Generated by VULONE's analysis model from the NVD record, CISA KEV and EPSS data on 19 September 2026. Confidence: high.

high priorityRemote code execution with no authentication required and a very high EPSS percentile, though the affected IE versions are legacy and largely retired.

What it is

Internet Explorer 6 through 9, plus the IE 10 Consumer Preview, mishandles objects in memory when a nonexistent object is accessed, producing a heap-based buffer overflow. A remote attacker can trigger this through crafted web content and execute arbitrary code in the context of the browsing user. It was demonstrated publicly by VUPEN at Pwn2Own 2012, so the flaw class and reachability are well understood.

Impact

Successful exploitation gives the attacker arbitrary code execution with the privileges of the IE process, typically the logged-on user. That enables installation of malware, data theft, or further lateral movement from the victim host.

Attack surface

Reached over the network via a web page or other content rendered by Internet Explorer; the CVSS vector AV:N/AC:M/Au:N indicates no authentication is required and only medium access complexity. User interaction is implied by browsing to attacker-controlled content, though the record does not state it explicitly.

Exploitation

Not listed in CISA KEV, but EPSS is 0.64962 (99.2nd percentile), indicating high modeled likelihood of exploitation activity. References document a live Pwn2Own demonstration and a US-CERT alert, confirming public proof-of-concept exploitation rather than theoretical risk.

What to do

• Apply Microsoft security bulletin MS12-037, which addresses this vulnerability, and prioritize it on any system still running IE 6 through 10 Consumer Preview.
• Upgrade or migrate off IE 6-9 and the IE 10 Consumer Preview to a supported browser version, since these releases are long out of support.
• Enforce network and endpoint controls that block or restrict browsing to untrusted sites, and disable legacy IE rendering modes where possible.
• Harden the browser with Protected Mode, DEP, and ASLR, and remove unnecessary plug-ins and ActiveX controls that expand the attack surface.

Detection

• Hunt for IE process crashes or heap corruption events (for example, mshtml.dll or iexplore.exe faults) on hosts running the affected versions.
• Monitor proxy, DNS, and firewall logs for IE clients reaching known exploit-hosting or Pwn2Own-related domains and suspicious drive-by pages.
• Alert on child processes spawned by iexplore.exe, such as cmd.exe, powershell.exe, or script hosts, which are abnormal for normal browsing.
• Review endpoint telemetry for memory-protection bypass attempts or shellcode-like behavior in the IE process space.

This assessment is produced automatically and is not human-reviewed. Verify against the vendor advisory before acting on it.