CVE-2020-3165Network attack vector

Unauthenticated BGP session via conditional MD5 bypass

Published Feb 26, 2020 · Updated Nov 15, 2024

Authentication bypass in Cisco NX-OS Software 9.2(1), 9.2(2), 9.2(3), and 9.3(1) allows remote attackers to establish BGP sessions without MD5. NX-OS skips BGP MD5 authentication when its VRF name exceeds 19 characters and the connecting peer omits MD5 despite device-side authentication. Exploitation requires traffic appearing to originate from an explicitly configured trusted peer and grants an unauthorized routing session.

CVSS severity8.2
High
EPSS probability1.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Cisco NX-OS Software 9.2(1), 9.2(2), 9.2(3), and 9.3(1) allows remote attackers to establish BGP sessions without MD5. NX-OS skips BGP MD5 authentication when its VRF name exceeds 19 characters and the connecting peer omits MD5 despite device-side authentication. Exploitation requires traffic appearing to originate from an explicitly configured trusted peer and grants an unauthorized routing session.

The record

CVE
CVE-2020-3165
Published
Feb 26, 2020
Updated
Nov 15, 2024
Vendor
ClamAV
Product
Cisco NX-OS Software
Classifications
CWE-798
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 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=9.2(1)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco NX-OS Softwareversion=9.2(1)

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/A:N
8.2NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
8.2Cisco Systems, Inc.CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N/E:X/RL:X/RC:X

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-798Use of Hard-coded Credentials

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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