Microsoft Internet Explorer Use-After-Free Vulnerability (CVE-2010-0806)

Severity Assessment

• Exploitability: 7/10 - Exploitation requires a user to view specially crafted web content in a vulnerable Internet Explorer version, but the public sources describe no authentication or privileges required.
• Impact: 9/10 - Successful exploitation could allow arbitrary code execution with the rights of the logged-on user; Microsoft notes that administrative users face greater impact.
• Weaponization Risk: 8/10 - NVD records exploitation in the wild in March 2010, and CISA later added the CVE to the Known Exploited Vulnerabilities catalog.
• Patch Urgency: 10/10 - Microsoft released MS10-018 on 2010-03-30, and CISA lists a 2026-06-03 remediation due date for covered federal systems.
• Detection Coverage: 3/10 - The cited sources do not provide stable hashes, domains, filenames, or other indicators, so detection depends on patch inventory, browser hardening, and process behavior.

CVE-2010-0806 has a CISA ADP CVSS 3.1 base score of 8.8/10 (High) with vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. NVD also lists a CVSS 2.0 base score of 9.3/10 (High).

Summary

CVE-2010-0806 is a use-after-free vulnerability in the Peer Objects component (iepeers.dll) in Microsoft Internet Explorer. NVD describes affected versions as Internet Explorer 6, Internet Explorer 6 SP1, and Internet Explorer 7. The vulnerability involves access to an invalid pointer after an object is deleted and can allow remote attackers to execute arbitrary code.

Microsoft published Security Advisory 981374 on 2010-03-09 for a vulnerability in Internet Explorer that could allow remote code execution. Microsoft later updated the advisory on 2010-03-30 after publishing MS10-018, the cumulative security update that addressed CVE-2010-0806 and other Internet Explorer vulnerabilities.

Microsoft describes CVE-2010-0806 as the Uninitialized Memory Corruption Vulnerability. NVD records exploitation in the wild in March 2010. Microsoft states that CVE-2010-0806 does not affect Internet Explorer 8, Windows 7, or Windows Server 2008 R2.

CISA added CVE-2010-0806 to the Known Exploited Vulnerabilities catalog on 2026-05-20. The CISA entry lists known ransomware campaign use as Unknown and notes that impacted Internet Explorer versions may be end-of-life or end-of-service, requiring mitigation or discontinuation where vendor updates are unavailable.

Exploit Chain

Stage 1: Malicious web content preparation

An attacker prepares specially crafted web content that targets Internet Explorer’s handling of objects in memory. Microsoft describes the vulnerable condition as access to an object that was not correctly initialized or had been deleted.

Stage 2: Hosting or delivery

Microsoft describes several possible delivery paths: an attacker-hosted website, a compromised website, a site that accepts user-provided content or advertisements, or an ActiveX control embedded in an application or Microsoft Office document that hosts the Internet Explorer rendering engine.

Stage 3: User interaction

The attacker must convince a user to view the malicious content or open the containing document. Microsoft explicitly notes that an attacker has no way to force users to view the attacker-controlled content.

Stage 4: Use-after-free condition

When a vulnerable Internet Explorer instance processes the crafted content, it may access an invalid pointer after object deletion, corrupting memory in the browser process.

Stage 5: Code execution

If exploitation succeeds, attacker-controlled code can run with the same rights as the logged-on user. Microsoft states that users with fewer privileges could be less impacted than users operating with administrative rights.

Detection Guidance

Patch and product inventory:

• Identify systems running affected Internet Explorer versions, especially Internet Explorer 6, Internet Explorer 6 SP1, and Internet Explorer 7.
• Apply MS10-018 or later cumulative Internet Explorer security updates where the platform remains supportable.
• Discontinue affected end-of-life or end-of-service Internet Explorer deployments when vendor mitigations are unavailable.

Browser hardening:

• Use Microsoft-documented workarounds where patching is delayed: set Internet and Local intranet security zones to High, prompt before or disable Active Scripting, and add only trusted sites to the Trusted sites zone.
• Preserve Internet Explorer Enhanced Security Configuration on Windows Server 2003 and Windows Server 2008, which Microsoft identifies as a mitigating factor for untrusted sites.

Behavioral monitoring:

• Monitor iexplore.exe for crashes after viewing web content.
• Investigate unexpected child processes, suspicious memory activity, or outbound connections from Internet Explorer immediately after browsing to untrusted content.
• Treat Office documents or applications that host the Internet Explorer rendering engine as possible exploit delivery paths when investigating suspicious behavior.

Indicators of Compromise

The cited CISA, NVD, and Microsoft sources do not provide stable network indicators, file hashes, filenames, registry keys, or command-and-control infrastructure for CVE-2010-0806 exploitation.

Potential investigation leads include:

• Vulnerable Internet Explorer versions rendering untrusted or newly visited web content.
• Internet Explorer crashes associated with suspicious or compromised web pages.
• Unexpected process creation or network activity from iexplore.exe.

These are behavioral leads only and should be correlated with patch status, browser version, and the source of the visited content.

Disclosure Timeline

Date	Event
2010-03-09	Microsoft published Security Advisory 981374 for an Internet Explorer vulnerability that could allow remote code execution.
2010-03-10	NVD published the CVE-2010-0806 entry and records exploitation in the wild in March 2010.
2010-03-10	Microsoft updated the advisory to restate email-vector mitigation and add a workaround for disabling the peer factory class in iepeers.dll.
2010-03-12	Microsoft added an automated Fix it option for the peer factory class workaround on Windows XP and Windows Server 2003.
2010-03-30	Microsoft published MS10-018, a cumulative Internet Explorer update that addressed CVE-2010-0806.
2026-05-20	CISA added CVE-2010-0806 to the Known Exploited Vulnerabilities catalog.
2026-05-21	NVD last modified the CVE-2010-0806 record.
2026-06-03	CISA KEV remediation due date for covered federal systems.

Sources & References

• Cybersecurity and Infrastructure Security Agency: Known Exploited Vulnerabilities Catalog - CVE-2010-0806 — Cybersecurity and Infrastructure Security Agency, 2026-05-20
• National Vulnerability Database: CVE-2010-0806 Detail — National Vulnerability Database, 2010-03-10
• Microsoft: Security Advisory 981374 — Microsoft, 2010-03-09
• Microsoft: Security Bulletin MS10-018 — Microsoft, 2010-03-30