CVE-2025-21208: Microsoft Windows Server 2008 R2 Service Pack 1 · Heap-based Buffer Overflow
Affects Microsoft Windows Server 2008 R2 Service Pack 1Source CVE Database V5
Not known to be exploited · CVSS 8.8 High.
Data as of 26 Oct 2026, 07:57 UTC
- EPSS
- 1.8% chance of exploitation in 30 days – higher than 78% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:CExploitation evidence
Disclosed: evidence found.
CVE published 11 Feb 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Microsoft Windows Server 2008 R2 Service Pack 1 | Affected
| Fixed in– |
AI-suggested
1. Disable the Routing and Remote Access Service (RRAS) if it is not essential to your network operations to eliminate the attack surface. 2. Restrict network access to RRAS ports and services using firewalls and network segmentation, allowing only trusted hosts and networks to communicate with RRAS. 3. Implement strict ingress filtering and VPN access controls to limit exposure to untrusted external networks. 4. Monitor network traffic and system logs for unusual or malformed packets targeting RRAS, and deploy intrusion detection/prevention systems with updated signatures once available. 5. Apply any official patches or security updates from Microsoft immediately upon release. 6. For organizations unable to patch promptly, consider deploying host-based application control or exploit mitigation technologies that can detect or block heap overflow exploitation techniques. 7. Conduct regular vulnerability assessments and penetration testing focused on legacy systems and remote access services. 8. Plan and execute migration strategies away from unsupported Windows Server 2008 R2 to supported versions with ongoing security updates.
Description
Windows Routing and Remote Access Service (RRAS) Remote Code Execution Vulnerability