CVE-2013-7331
CVE-2013-7331 is a security flaw in Microsoft Internet Explorer, Microsoft’s old web browser, still built into Windows. Attackers can read information from Microsoft Internet Explorer that should be private. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 25 May 2022.[1]
Microsoft Internet Explorer is in things households have, such as phones, computers, browsers and everyday apps, so the fix matters at home as much as at work. Microsoft has published a fix or advice.
Description
CISA calls it an information disclosure in Microsoft Internet Explorer. In its words: “An information disclosure vulnerability exists in Internet Explorer which allows resources loaded into memory to be queried. This vulnerability could allow an attacker to detect anti-malware applications.”[1]
The CVE record adds: “The Microsoft.XMLDOM ActiveX control in Microsoft Windows 8.1 and earlier allows remote attackers to determine the existence of local pathnames, UNC share pathnames, intranet hostnames, and intranet IP addresses by examining error codes, as demonstrated by a res:// URL, and exploited in the wild in February 2014.”[2]
The underlying weakness is information exposure (CWE-200), in MITRE’s list of common software weaknesses.
It scores 6.5 out of 10 on the Common Vulnerability Scoring System, which rates it medium, scored by the organisation that published the CVE using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; Microsoft’s advisory has them[3]. CISA names the product as Microsoft Internet Explorer.
Every device with Microsoft Internet Explorer needs the update.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 25 May 2022, 3,010 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 15 Jun 2022 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 50%. That’s in the top 2% of the flaws it scores.[4]
CISA assesses it as automatable: attackers can run it against many targets at once.
CISA doesn’t say who was attacked, or how.
Fix
Microsoft has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]
- Update Microsoft Internet Explorer now.Install the latest update from Microsoft on every device that has it, and restart when asked. Then turn on automatic updates, so the next fix arrives on its own.
- If there’s no update, stop using it.CISA’s advice when a flaw being used in attacks has no fix is to stop using the product until it does.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 6.5.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 50%.[4] |
See also
Other Microsoft Internet Explorer flaws
- CVE-2010-0806: use-after-free ·
- CVE-2010-0249: use-after-free ·
- CVE-2010-3962: uninitialized memory corruption ·
- CVE-2013-3893: resource management errors ·
- CVE-2012-4792: use-after-free ·
- CVE-2013-3163: memory corruption ·
Other Microsoft flaws
- CVE-2026-96951, Microsoft Windows: command injection ·
- CVE-2026-65660, Microsoft SharePoint: code injection ·
- CVE-2026-85880, Microsoft Windows: heap-based buffer overflow ·
- CVE-2026-81963, Microsoft Windows: link following ·
- CVE-2019-1068, Microsoft SQL Server: remote code execution ·
Other information exposure flaws
- CVE-2025-68686, Fortinet FortiOS: exposure of sensitive information to an unauthorized actor ·
- CVE-2026-20133, Cisco Catalyst SD-WAN Manager: exposure of sensitive information to an unauthorized actor ·
- CVE-2025-31125, Vitejs: improper access control ·
- CVE-2021-41277, Metabase: geoJSON API local file inclusion ·
- CVE-2024-24919, Check Point Quantum Security Gateways: information disclosure ·
Added the same day
- CVE-2019-3010, Oracle Solaris: privilege escalation ·
- CVE-2016-7256, Microsoft Windows: open type font remote code execution ·
- CVE-2016-3393, Microsoft Windows: graphics device interface (GDI) remote code execution ·
- CVE-2016-1010, Adobe Flash Player and AIR: integer overflow ·
- CVE-2016-0984, Adobe Flash Player and AIR: use-after-free ·
Every Microsoft flaw on CISA’s list · Everything added in May 2022
References
- ^ Cybersecurity and Infrastructure Security Agency. “Microsoft Internet Explorer Information Disclosure Vulnerability”. Known Exploited Vulnerabilities Catalog, added 25 May 2022.
- ^ National Institute of Standards and Technology. “CVE-2013-7331 Detail”. National Vulnerability Database, published 26 Feb 2014.
- ^ Microsoft. Advisories and fixes: docs.microsoft.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.502, percentile 98.9, 31 Oct 2026.
- CVE Program. “CVE-2013-7331”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.