CVE-2006-4650
Cisco IOS 12.0, 12.1, and 12.2, when GRE IP tunneling is used and the RFC2784 compliance fixes are missing, does not verify the offset field of a GRE packet during decapsulation, which leads to an integer overflow that references data from incorrect memory locations, which allows remote attackers to inject crafted packets into the routing queue, possibly bypassing intended router ACLs.
Key facts
- CVSS score
- 2.6 (v2.0)
- Severity
- LOW
- CVSS vector
AV:N/AC:H/Au:N/C:P/I:N/A:N- EPSS score
- 3.2% (88th percentile)
- In CISA KEV
- No
- In EU EUVD
- Yes (EUVD-2006-4638)
- Published
- September 9, 2006
- NVD last modified
- June 16, 2026
- Status
- Modified
EU Vulnerability Database (EUVD)
This vulnerability is also tracked by ENISA as EUVD-2006-4638 in the EU Vulnerability Database. Last updated in EUVD on August 7, 2024.
View on the EU Vulnerability DatabaseAffected products
- cisco / ios
- cisco / ios
- cisco / ios
References
- http://secunia.com/advisories/21783
- http://securityreason.com/securityalert/1526
- http://securitytracker.com/id?1016799
- http://www.cisco.com/en/US/tech/tk827/tk369/tsd_technology_security_response09186a008072cd7b.html
- http://www.osvdb.org/28590
- http://www.phenoelit.de/stuff/CiscoGRE.txt(Vendor Advisory)
- http://www.securityfocus.com/archive/1/445322/100/0/threaded
- http://www.securityfocus.com/bid/19878
- http://www.vupen.com/english/advisories/2006/3502
- https://exchange.xforce.ibmcloud.com/vulnerabilities/28786
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A5713
Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS
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