Microsoft Windows Buffer Overflow
CVE-2008-4250 is a high-severity improper control of generation of code vulnerability in Windows 2000 from Microsoft, with a CVSS 2.0 base score of 10.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. CISA added it to the Known Exploited Vulnerabilities catalogue on May 20, 2026, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Check which version of Windows 2000 you run against the affected versions below, and install the vendor's latest release.
- CISA's required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- Read the advisory on secunia.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Microsoft | Windows 2000 | Not specified in the record | Not stated |
| Microsoft | Windows Server 2003 | Not specified in the record | Not stated |
| Microsoft | Windows Server 2008 | Not specified in the record | Not stated |
| Microsoft | Windows Vista | Not specified in the record | Not stated |
| Microsoft | Windows Xp | Not specified in the record | Not stated |
Version data comes from NVD's product matching. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Access vector
- NetworkCan be exploited remotely over a network.
- Access complexity
- LowNo special conditions are needed.
- Authentication
- NoneNo login is needed.
- Confidentiality
- CompleteAll data can be read.
- Integrity
- CompleteAny data can be modified.
- Availability
- CompleteThe system can be shut down completely.
Vector: AV:N/AC:L/Au:N/C:C/I:C/A:C. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.8 | Critical | CISA (ADP) |
| CVSS 2.0 | 10.0 | High | NVD |
Official description
The Server service in Microsoft Windows 2000 SP4, XP SP2 and SP3, Server 2003 SP1 and SP2, Vista Gold and SP1, Server 2008, and 7 Pre-Beta allows remote attackers to execute arbitrary code via a crafted RPC request that triggers the overflow during path canonicalization, as exploited in the wild by Gimmiv.A in October 2008, aka "Server Service Vulnerability."
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Control of Generation of Code
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
How developers prevent this class of flaw
- Refactor your program so that you do not have to dynamically generate code.
- Run your code in a jail or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
- Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
More Improper Control of Generation of Code vulnerabilities (CWE-94)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: total).
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- marc.info/?l=bugtraq&m=122703006921213&w=2Issue Tracking, Mailing List, Third Party Advisory
- kb.cert.org/vuls/id/827267Third Party Advisory, US Government Resource
- us-cert.gov/cas/techalerts/TA09-088A.htmlThird Party Advisory, US Government Resource
- exchange.xforce.ibmcloud.com/vulnerabilities/46040Third Party Advisory, VDB Entry
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2008-4250US Government Resource
Technical write-ups (may include proof of concept)
- exploit-db.com/exploits/6824Exploit, Third Party Advisory, VDB Entry
- exploit-db.com/exploits/6841Exploit, Third Party Advisory, VDB Entry
- exploit-db.com/exploits/7104Exploit, Third Party Advisory, VDB Entry
- exploit-db.com/exploits/7132Exploit, Third Party Advisory, VDB Entry
Other references
- blogs.securiteam.com/index.php/archives/1150Permissions Required
Other vulnerabilities in Windows 2000
- 7.8 High severity
- 7.8 High severity
- 9.3 High severity
Microsoft DirectX NULL Byte Overwrite Exploited
- 7.8 High severity
Microsoft Windows Privilege Escalation Exploited
- 7.8 High severity
Microsoft Windows Privilege Escalation Exploited
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