CVE-2022-20758Network attack vector

BGP process restart via malformed EVPN update

Published Apr 15, 2022 · Updated Nov 6, 2024

Denial of service in Cisco IOS XR Software allows remote attackers to restart BGP on affected devices via a crafted EVPN update. The BGP EVPN implementation incorrectly processes specific EVPN attributes in a received update instead of safely rejecting the malformed message. Exploitation requires a configured, trusted BGP peer for the L2VPN EVPN address family or injection into that peer’s existing TCP connection; client traffic and other peers cannot trigger the BGP-process restart.

CVSS severity6.8
Medium
EPSS probability1.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Denial of service in Cisco IOS XR Software allows remote attackers to restart BGP on affected devices via a crafted EVPN update. The BGP EVPN implementation incorrectly processes specific EVPN attributes in a received update instead of safely rejecting the malformed message. Exploitation requires a configured, trusted BGP peer for the L2VPN EVPN address family or injection into that peer’s existing TCP connection; client traffic and other peers cannot trigger the BGP-process restart.

The record

CVE
CVE-2022-20758
Published
Apr 15, 2022
Updated
Nov 6, 2024
Vendor
ClamAV
Product
Cisco IOS XR Software
Classifications
CWE-399, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 15, 2022CVE publishedPublication date reported by the CVE source.
  2. Nov 6, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=n/a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco IOS XR Softwareversion=n/a

Published CVSS scores

6.8CiscoCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H/E:X/RL:X/RC:X
7.1NIST NVDAV:N/AC:M/Au:N/C:N/I:N/A:C

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-399Resource Management Errors
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo