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…
- 2.6LowCVSS base score
- 3.2%Exploitation in 30 daysEPSS · top 12% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By mitre
- 1 day later
· 1 day later
Published
- 18 years later
· 18 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 2.0 | Low2.6 | AV:N/AC:H/Au:N/C:P/I:N/A:N |
- EPSS (exploitation in 30 days)
- 3.2% · top 12% of all CVEs (10 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 2.6.
Affected products
n/a
- affected n/a
References
11
- ADV-2006-3502 (opens in a new tab)vdb-entryx_refsource_VUPENx_transferred
- 1016799 (opens in a new tab)vdb-entryx_refsource_SECTRACKx_transferred
- 28590 (opens in a new tab)vdb-entryx_refsource_OSVDBx_transferred
- 20060906 Cisco IOS GRE issue (opens in a new tab)mailing-listx_refsource_BUGTRAQx_transferred
- http://www.phenoelit.de/stuff/CiscoGRE.txt (opens in a new tab)x_refsource_MISCx_transferred
- 21783 (opens in a new tab)third-party-advisoryx_refsource_SECUNIAx_transferred
- 1526 (opens in a new tab)third-party-advisoryx_refsource_SREASONx_transferred
- 19878 (opens in a new tab)vdb-entryx_refsource_BIDx_transferred
- 20060906 Cisco IOS GRE Decapsulation Vulnerability (opens in a new tab)vendor-advisoryx_refsource_CISCOx_transferred
- oval:org.mitre.oval:def:5713 (opens in a new tab)vdb-entrysignaturex_refsource_OVALx_transferred
- cisco-ios-gre-acl-bypass(28786) (opens in a new tab)vdb-entryx_refsource_XFx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2006-4638 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2006-4650)Record last updated .