CVE-2009-2055

Name: CVE-2009-2055
Creator: NVD / NIST
Published: 2009-08-19T17:30:01.047+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.9/10Actively ExploitedEPSS 3.33%

Last modified Jun 16, 2026

CVE-2009-2055 is a medium-severity vulnerability rated 5.9/10 on the CVSS scale. Cisco IOS XR 3.4.0 through 3.8.1 allows remote attackers to cause a denial of service (session reset) via a BGP UPDATE message with an invalid attribute, as demonstrated in the wild on 17 August 2009.. CISA has confirmed active exploitation in the wild. EPSS estimates a 3.33% chance of exploitation in the next 30 days.

Description

Cisco IOS XR 3.4.0 through 3.8.1 allows remote attackers to cause a denial of service (session reset) via a BGP UPDATE message with an invalid attribute, as demonstrated in the wild on 17 August 2009.

Metrics

CVSS 3.1

5.9/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

3.33%

87.1th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Apr 15, 2022.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cisco	Ios Xr	3.4
Cisco	Ios Xr	3.4.0
Cisco	Ios Xr	3.4.1
Cisco	Ios Xr	3.4.2
Cisco	Ios Xr	3.4.3
Cisco	Ios Xr	3.5
Cisco	Ios Xr	3.5.2
Cisco	Ios Xr	3.5.3
Cisco	Ios Xr	3.5.4
Cisco	Ios Xr	3.6.0
Cisco	Ios Xr	3.6.1
Cisco	Ios Xr	3.6.2
Cisco	Ios Xr	3.6.3
Cisco	Ios Xr	3.7.0
Cisco	Ios Xr	3.7.1
Cisco	Ios Xr	3.7.2
Cisco	Ios Xr	3.7.3
Cisco	Ios Xr	3.8.0
Cisco	Ios Xr	3.8.1

References

http://mailman.nanog.org/pipermail/nanog/2009-August/012719.htmlMailing List
http://securitytracker.com/id?1022739Broken Link
http://www.cisco.com/en/US/products/products_security_advisory09186a0080af150f.shtmlPatch, Vendor Advisory
http://mailman.nanog.org/pipermail/nanog/2009-August/012719.htmlMailing List
http://securitytracker.com/id?1022739Broken Link
http://www.cisco.com/en/US/products/products_security_advisory09186a0080af150f.shtmlPatch, Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2009-2055US Government Resource

Timeline

Published: Aug 19, 2009
Last Modified: Jun 16, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2009-2055?

How severe is CVE-2009-2055?

CVE-2009-2055 has a CVSS score of 5.9/10 (MEDIUM severity). The EPSS model estimates a 3.33% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2009-2055?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2009-2055?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST