CVE-2008-4250: Microsoft Windows Buffer Overflow Vulnerability

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Yes, if you run Microsoft Windows. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-05-20, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-06-03; treat that as the outer limit, not the target.
• EPSS 98.8%, percentile 99.9: FIRST’s model estimates a 98.8% chance of exploitation activity in the next 30 days, higher than 99.9% of all scored CVEs (very high). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.

What it is

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."

CISA’s summary

Microsoft Windows contains a buffer overflow vulnerability in the Windows Server Service that allows remote attackers to execute arbitrary code via a crafted RPC request that triggers an overflow during path canonicalization.

Weakness type: CWE-119, CWE-94.

Product: Microsoft Windows · Assigned by: microsoft · Published: 2008-10-23

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: none (no login)
• User interaction: none
• Scope: unchanged

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: added 2026-05-20; federal due date 2026-06-03. Known ransomware use: Unknown.
• CISA 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.
• CISA SSVC assessment: exploitation active, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 98.75% probability of exploitation activity in the next 30 days; percentile 99.9.

Timeline

• 2008-10-23 — CVE record published by microsoft
• 2026-05-20 — Added to CISA’s Known Exploited Vulnerabilities catalog
• 2026-05-21 — CVE record last updated
• 2026-06-03 — CISA remediation deadline for US federal agencies

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. SSRT080164 marc.info
2. MS08-067 docs.microsoft.com
3. Listed in CISA KEV notes (learn.microsoft.com) learn.microsoft.com

Vulnerability records

1. CVE.org record CVE-2008-4250 cve.org
2. NVD entry CVE-2008-4250 nvd.nist.gov

Government

1. CISA Known Exploited Vulnerabilities catalog entry cisa.gov

Other references from the CVE record and advisory

1. 32326 secunia.com
2. VU#827267 kb.cert.org
3. 1021091 securitytracker.com
4. 7132 exploit-db.com
5. 6841 exploit-db.com
6. 31874 securityfocus.com
7. blogs.securiteam.com blogs.securiteam.com
8. 6824 exploit-db.com
9. ADV-2008-2902 vupen.com
10. win-server-rpc-code-execution(46040) exchange.xforce.ibmcloud.com
11. 20081026 Windows RPC MS08-067 FAQ document released securityfocus.com
12. TA08-297A us-cert.gov
13. 7104 exploit-db.com
14. TA09-088A us-cert.gov
15. oval:org.mitre.oval:def:6093 oval.cisecurity.org
16. 20081027 Windows RPC MS08-067 FAQ document updated securityfocus.com

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