CVE-2010-0806: Microsoft Internet Explorer Use-After-Free Vulnerability
Microsoft Internet Explorer contains an use-after-free vulnerability that could allow remote attackers to execute arbitrary code via vectors involving access to an invalid pointer after the deletion of an object. The impacted product could be end-of-life (EoL) and/or end-of-service (EoS). Users should discontinue product utilization.
Overview
A use-after-free flaw in the Peer Objects component (iepeers.dll) of Internet Explorer 6 and 7 allows a remote, unauthenticated attacker to execute arbitrary code on a victim's machine. The flaw was actively exploited in the wild before a patch was available. Internet Explorer 5.01, 6, and 7 are affected; IE 8, Windows 7, and Windows Server 2008 R2 are not. Affected versions are end-of-life, and Microsoft's guidance is to discontinue use if patching is not possible.
Vulnerability details
The iepeers.dll component, which provides Web Folder and printing support in Internet Explorer, fails to invalidate a pointer after the object it references is freed. In a use-after-free condition, the browser retains a dangling pointer to memory that has been released. If an attacker can control the contents of that freed memory region before the stale pointer is dereferenced, the browser may execute attacker-supplied data as code. The flaw is triggered by the browser's own object lifecycle management when processing attacker-controlled content, not by a missing input validation check at a trust boundary.
An attacker delivers a specially crafted HTML page or Microsoft Office document to the victim. When the victim opens the page or document in an affected version of Internet Explorer, the content triggers the object deletion and subsequent invalid pointer dereference inside iepeers.dll. Successful exploitation gives the attacker arbitrary code execution running under the privileges of the IE process. If the victim is logged in as an administrator, the attacker gains full administrative access. No authentication is required from the attacker; the only precondition is that the victim uses IE 6 or IE 7 and can be directed to the malicious content.
Severity and impact
Exploitation status
This vulnerability is confirmed as actively exploited in the wild — it is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog.
Detection and monitoring
- Monitor for iexplore.exe spawning unexpected child processes (cmd.exe, powershell.exe, wscript.exe, or other shells) on hosts running IE 6 or IE 7. A browser process creating a command interpreter is a strong indicator of post-exploitation activity and does not occur during normal browsing.
- Review endpoint crash logs and Windows Event Log entries for access violation or heap corruption faults originating from iexplore.exe referencing iepeers.dll. Repeated or patterned crashes of this type on the same host, particularly following visits to unfamiliar sites, warrant investigation as exploitation attempts.
Remediation
Additional hardening
- Apply Microsoft Security Bulletin MS10-018, which addresses this vulnerability for all supported IE versions. Where patching is not possible, CISA guidance is to discontinue use of the affected product entirely.
- Enable Data Execution Prevention (DEP) for Internet Explorer 6 and 7. Microsoft confirmed DEP as a partial mitigation that can block execution of attacker-supplied shellcode in some exploitation scenarios, though it is not a complete substitute for patching.
- Set the Internet zone security level to High and disable Active Scripting in Internet Options. This reduces the attack surface by prompting before running ActiveX controls and scripts, which are common delivery mechanisms for the crafted content that triggers this flaw.
- Restrict outbound web access from hosts still running IE 6 or IE 7 to known, approved destinations via proxy or firewall policy. Limiting the sites these browsers can reach reduces the probability of a user loading attacker-controlled content.
Key dates
References
- http://www.kb.cert.org/vuls/id/744549
- https://docs.microsoft.com/en-us/security-updates/securitybulletins/2010/ms10-018
- https://learn.microsoft.com/en-us/security-updates/securitybulletins/2010/ms10-018
- https://learn.microsoft.com/en-us/security-updates/securityadvisories/2010/981374
- https://nvd.nist.gov/vuln/detail/CVE-2010-0806
- http://secunia.com/advisories/38860
Frequently asked questions
Does CVE-2010-0806 affect my FedRAMP authorization?
If Microsoft Internet Explorer runs inside your authorization boundary, yes. CVE-2010-0806 is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, with a remediation deadline of June 3, 2026 that has already passed. For a FedRAMP-authorized service, an unpatched KEV inside the boundary is a finding. An overdue one is a finding your assessor and sponsoring agency can see right now. Your options are to remediate it immediately or formally document the mitigation and the delay.
How does Knox help me handle CVE-2010-0806?
Knox does not patch your software. Remediating Microsoft Internet Explorer is your responsibility under the FedRAMP shared-responsibility model. What Knox provides is the pre-authorized, single-tenant boundary to remediate within, plus continuous compliance monitoring and audit-artifact coverage to document the fix for your next assessment. The remediation work is yours to carry out; maintaining a defensible compliance posture while you do it is not something you have to manage on your own.
How does Knox's monitoring help with vulnerabilities like this?
Knox's automated continuous monitoring platform watches your environment for newly disclosed vulnerabilities and compliance issues on a continuous basis. For a CVE like CVE-2010-0806, that means exposure surfaces during ongoing monitoring rather than only when an assessor flags it at review time, giving your team earlier visibility and more time to act.
How do I get FedRAMP authorized with Knox?
Knox runs a FedRAMP-as-a-Service platform. It gives SaaS vendors a pre-authorized cloud boundary on AWS, Azure, and GCP. Your application inherits 60-80% of the required security controls. You reach FedRAMP authorization in about 90 days for roughly 90% less than the traditional $3.5M path. Book a meeting and Knox will map your path to authorization.
CVE-2010-0806's remediation deadline of June 3, 2026 has passed. What happens now?
An unremediated CVE-2010-0806 is already a Plan of Action and Milestones (POA&M) item, and a growing POA&M list is what turns a routine continuous-monitoring review into a difficult agency conversation. Closing it out now and formally documenting why the deadline was missed is what keeps your authorization intact and the agency relationship on solid footing.
Ready to achieve FedRAMP authorization in 90 days or less?
Schedule a meeting to discuss scope, parse readiness, and map your company’s accelerated path to FedRAMP authorization.
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