Use-after-free vulnerability in Microsoft Internet Explorer 6 through 10 allows remote attackers to execute arbitrary code via a crafted web site that triggers access to a deleted object, as demonstrated by VUPEN during a Pwn2Own competition at CanSecWest 2013, aka "Internet Explorer Use After Free Vulnerability," a different vulnerability than CVE-2013-1308 and CVE-2013-1309.
Conclusion & alert: CVE-2013-2551 is rated Critical Active Threat (90/100): CVSS High severity, with high exploitation likelihood (EPSS 73.92%, 99th percentile). Core evidence: CISA KEV confirms active exploitation (added 2022-03-28) affecting Microsoft / Internet Explorer. a weakness (CWE-416) Unauthenticated remote administrative access may be possible. Mandatory action: The CISA remediation deadline has passed—treat as an emergency patch priority.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
: Microsoft Internet Explorer Use-After-Free Vulnerability · CISA KEV detail
: 2022-03-28
: 2022-04-18
: Apply updates per vendor instructions.
| EDB-ID | Source | Kind | Published | Link |
|---|---|---|---|---|
| 26175 | exploit_db | edb | 2013-06-13 | Exploit-DB ↗ |
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 92.45% | 73.92% | -18.53% |
| 2 | 2026-05-24 | 92.29% | 92.45% | +0.16% |
| 3 | 2026-05-22 | — | 92.29% | — |
Full EPSS history (26 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 8.8 | 3.1 | HIGH |
|
2.8 | 5.9 | [email protected] |
| 8.8 | 3.1 | HIGH |
|
2.8 | 5.9 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
| 9.3 | 2.0 | HIGH |
|
8.6 | 10.0 | [email protected] |
: CWE 416 User-after-free http://cwe.mitre.org/data/definitions/416.html
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| microsoft | internet_explorer | 6 | cpe:2.3:a:microsoft:internet_explorer:6:*:*:*:*:*:*:* |
| microsoft | internet_explorer | 7 | cpe:2.3:a:microsoft:internet_explorer:7:*:*:*:*:*:*:* |
| microsoft | internet_explorer | 8 | cpe:2.3:a:microsoft:internet_explorer:8:*:*:*:*:*:*:* |
| microsoft | internet_explorer | 9 | cpe:2.3:a:microsoft:internet_explorer:9:-:*:*:*:*:*:* |
| microsoft | internet_explorer | 10 | cpe:2.3:a:microsoft:internet_explorer:10:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| http://h30499.www3.hp.com/t5/HP-Security-Research-Blog/Pwn2Own-2013/ba-p/5981157 | Broken Link Third Party Advisory |
| http://twitter.com/VUPEN/statuses/309479075385327617 | Broken Link |
| http://twitter.com/thezdi/statuses/309452625173176320 | Not Applicable |
| http://www.us-cert.gov/ncas/alerts/TA13-134A | Third Party Advisory US Government Resource |
| https://docs.microsoft.com/en-us/security-updates/securitybulletins/2013/ms13-037 | Patch Vendor Advisory |
| https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A16317 | Broken Link |
| https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2013-2551 | US Government Resource |