01 Record

CVE-2009-2055

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.

MediumKEVPUBLISHEDCNA: cisco

CNA base score5.9 CVSS v3.xCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

View raw JSON

02 Description

03 Exploitation and scoring

Exploitation

Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2022-03-25. Federal remediation due 2022-04-15.

SSVC decision

ExploitationactiveCISA reports credible evidence of active exploitation.
AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

3.31% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 88.5% of scored records. A rank, not a probability.

NVD base score

5.9 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

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

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-16.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published

2009-08-19 17:00Z17 YR AGO

Last updated

2026-01-12 20:39Z9 MO AGO

Reserved

2009-06-12

Assigning CNA

cisco

Record state

PUBLISHED

Severity

Medium (CVSS 5.9)

CNA CVSS vector

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

Weaknesses

CWE-20Improper Input ValidationClass

Data version

5.2

Document digest

e0b878e1f18a43b3833fd600f873f8f499ba021453ac867bad488a409acaaa46

05 Affected products

VendorProductVersionsPlatforms

ciscoios_xrNot specified—

06 References

mailman.nanog.org[nanog] 20090817 RE: Anyone else seeing "(invalid or corrupt AS path) 3 bytes E01100" ?http://mailman.nanog.org/pipermail/nanog/2009-August/012719.htmlmailing-listx_refsource_MLIST
securitytracker.com1022739http://securitytracker.com/id?1022739vdb-entryx_refsource_SECTRACK
www.cisco.com20090818 Cisco IOS XR Software Border Gateway Protocol Vulnerabilityhttp://www.cisco.com/en/US/products/products_security_advisory09186a0080af150f.shtmlvendor-advisoryx_refsource_CISCO
www.cisa.govhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2009-2055government-resource