Microsoft Outlook Express: Heap-Based Buffer Overflow (CVE-2007-3897)
Published Sources: CVE.org
What is affected, what to do
Heap-based buffer overflow in Microsoft Outlook Express 6 and earlier, and Windows Mail for Vista, allows remote Network News Transfer Protocol (NNTP) servers to execute arbitrary code via long NNTP responses that trigger memory corruption.
The available sources name no fixed version. Check the vendor guidance in the references below.
- Affected
- Microsoft Outlook Express
lte *..6.0 - Microsoft Outlook Express
eq 6.0..6.0
- Microsoft Outlook Express
Not sure whether and how you are affected? Ask a question about this vulnerability
Metrics
—
Priority
No value is available for this vulnerability.
—
CVSS v3
No value is available for this vulnerability.
54.6 %
EPSS score
High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
Source: FIRST EPSS, percentile 99.01
Show all metrics
- Severity
- Not rated
Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 78.42 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- no public PoC known
EPSS score
The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.
Read in glossary- 54.6 %
- High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
EPSS percentile
The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.
Read in glossary- 99.01
- Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- —
- Published
Detection rules
No NEOSEC detection rule is available for this vulnerability yet.
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
Description
Heap-based buffer overflow in Microsoft Outlook Express 6 and earlier, and Windows Mail for Vista, allows remote Network News Transfer Protocol (NNTP) servers to execute arbitrary code via long NNTP responses that trigger memory corruption.
Source: NVD (NIST), cvelistv5
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Affected versions | Fixed in | ||
|---|---|---|---|
| microsoft | outlook_express |
|
|
| microsoft | windows_mail |
|
|
Vendors and products
References & sources
- securitytracker.com1018785Vulnerability database, x_refsource_SECTRACK, Third-party advisory, Vulnerability database
- securityfocus.comHPSBST02280Vendor advisory, x_refsource_HP, Third-party advisory, Vulnerability database
- oval.cisecurity.orgoval:org.mitre.oval:def:1706Vulnerability database, signature, x_refsource_OVAL, Third-party advisory
- docs.microsoft.comMS07-056Vendor advisory, x_refsource_MS, Patch, Vendor advisory
- securityfocus.com20071010 Re: iDefense Security Advisory 10.09.07: Microsoft Windows Mail and Outlook Express NNTP Protocol Heap OverflowMailing list, x_refsource_BUGTRAQ, Third-party advisory, Vulnerability database
- labs.idefense.com20071009 Microsoft Windows Mail and Outlook Express NNTP Protocol Heap OverflowThird-party advisory, x_refsource_IDEFENSE, Broken link
- vupen.comADV-2007-3436Vulnerability database, x_refsource_VUPEN, Permissions required, Third-party advisory
- securitytracker.com1018786Vulnerability database, x_refsource_SECTRACK, Third-party advisory, Vulnerability database
- securityfocus.com25908Vulnerability database, x_refsource_BID, Third-party advisory, Vulnerability database
- us-cert.govTA07-282AThird-party advisory, x_refsource_CERT, Third-party advisory, US government resource
- secunia.com27112Third-party advisory, x_refsource_SECUNIA, Third-party advisory
Embed badge
Show the severity and KEV status of this vulnerability on your site – with a link back here. The image is updated hourly.
<a href="https://intel.neosec.eu/en/cve/CVE-2007-3897"><img src="https://intel.neosec.eu/badge/cve/CVE-2007-3897.svg?lang=en" alt="CVE-2007-3897 – NEOSEC Intel" height="20"></a>