CVE-2009-2055Cisco IOS XR Border Gateway Protocol (BGP) Denial-of-Service Vulnerability

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.

5.9 MEDIUMEPSS 3.31%⚡ Known Exploited (CISA KEV)NVD: Analyzed

Last updated: 2026-06-16 23:08 UTC

OverviewCVSS details

5.9MEDIUMCVSS 3.1

Score source: CISA-ADP
NVD status: Analyzed
Published: Aug 19, 2009
Assigner: cisco

Affected

ios xr (cisco)

Versions: 3.4 · 3.4.0

All affected versions →

Exploitation

Public exploit: None listed
CISA KEV: Listed · Mar 25, 2022
KEV due date: Apr 15, 2022
Ransomware use: Unknown
SSVC: Exploitation active · Automatable no · Impact partial

EPSS · FIRST, scored Nov 7

3.31%chance of exploitation in 30 days

Higher than 88.64% of CVEs

CVSS 3.1 · CISA-ADP

5.9Medium

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

Attack vector: Network
Attack complexity: High
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: None
Integrity impact: None
Availability impact: High

CVSS 2.0 · NVD

4.3Medium

AV:N/AC:M/Au:N/C:N/I:N/A:P

Attack vector: Network
Attack complexity: Medium
Authentication: None
Confidentiality impact: None
Integrity impact: None
Availability impact: Partial

NVD status: Analyzed

Overview Affected Products References

NVD CVE.org

Overview

Severity

Score	Severity	Version	Vector String
5.9	MEDIUM	3.1CISA-ADP	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
4.3	MEDIUM	2.0NVD	AV:N/AC:M/Au:N/C:N/I:N/A:P

CISA required action

⚡ Known exploited · remediation due Apr 15, 2022

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Details

CVE ID: CVE-2009-2055
Status: Analyzed
Assigner (CNA): cisco
Published: Aug 19, 2009
Last modified: 2026-06-16 23:08 UTC
Weaknesses: CWE-20

Sources

Refreshed hourly from the sources above. Last fetched 2026-11-08 12:45 UTC.