CVE-2006-2382: Microsoft Internet Explorer heap buffer overflow via crafted UTF-8 HTML

Automated analysis

Generated by VULONE's analysis model from the NVD record, CISA KEV and EPSS data on 20 September 2026. Confidence: medium.

high priorityThe flaw allows unauthenticated remote code execution with complete impact and has a high EPSS score, though it affects only legacy IE versions and is not in KEV.

What it is

Internet Explorer 5.01 SP4 and 6 SP1 and earlier contain a heap-based buffer overflow that occurs when crafted UTF-8 encoded HTML causes size discrepancies during conversion to Unicode. Successful exploitation allows remote code execution in the context of the browsing user, making it a serious client-side flaw for any organization still running these legacy IE versions.

Impact

An attacker can execute arbitrary code with the privileges of the user running Internet Explorer, leading to full system compromise if that user has administrative rights. The CVSS 2.0 vector rates confidentiality, integrity, and availability impact as complete.

Attack surface

The flaw is reached over the network by viewing a malicious web page or HTML email rendered by the vulnerable IE version; no authentication is required, but user interaction (opening the page or message) is needed. The CVSS vector AV:N/AC:L/Au:N confirms remote, unauthenticated reachability.

Exploitation

The record is not listed in CISA KEV and no ransomware usage is documented, but EPSS is high at 0.48569 (98.8th percentile), indicating a meaningful probability of exploitation activity. Reference tags are advisory and government resources only, with no public exploit tag supplied.

What to do

• Apply Microsoft security bulletin MS06-021, which addresses this vulnerability, or upgrade to a supported Internet Explorer version.
• If legacy IE cannot be patched, restrict browsing to trusted sites and disable active scripting where operationally feasible.
• Block or filter untrusted HTML email and web content at the gateway to reduce exposure to crafted UTF-8 pages.
• Retire or isolate systems still running IE 5.01 SP4, IE 6 SP1, or earlier from general internet access.

Detection

• Monitor for IE process crashes or unexpected child processes spawned from iexplore.exe, which may indicate heap corruption exploitation.
• Review proxy and web logs for requests to known malicious or suspicious HTML pages from hosts running legacy IE versions.
• Use endpoint detection to flag anomalous memory corruption behavior or code execution originating from the browser process.
• Audit installed IE versions across the estate to identify unpatched hosts matching the affected product range.

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