CVE-2019-15989Network attack vector

BGP process restart via malformed iBGP attribute

Published Jan 26, 2020 · Updated Nov 15, 2024

Denial of service in Cisco IOS XR Software allows remote attackers to restart the BGP process via a malformed iBGP update attribute. The BGP implementation incorrectly processes a specific non-transitive attribute instead of safely rejecting the malformed update, causing the routing process to restart. Exploitation requires a configured valid BGP peer or injection into an existing peer TCP connection, and the non-transitive attribute limits propagation to iBGP.

CVSS severity8.6
High
EPSS probability1.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Cisco IOS XR Software allows remote attackers to restart the BGP process via a malformed iBGP update attribute. The BGP implementation incorrectly processes a specific non-transitive attribute instead of safely rejecting the malformed update, causing the routing process to restart. Exploitation requires a configured valid BGP peer or injection into an existing peer TCP connection, and the non-transitive attribute limits propagation to iBGP.

The record

CVE
CVE-2019-15989
Published
Jan 26, 2020
Updated
Nov 15, 2024
Vendor
ClamAV
Product
Cisco IOS XR Software
Classifications
CWE-754, T1498
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 26, 2020CVE publishedPublication date reported by the CVE source.
  2. Nov 15, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=unspecified <n/a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco IOS XR Softwareversion=unspecified <n/a

Published CVSS scores

8.6CiscoCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:X/RL:X/RC:X
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P
8.6NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-754Improper Check for Unusual or Exceptional Conditions
T1498Network Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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