CVE-2022-20824

Root code execution or reload via malformed messages

Published Aug 25, 2022 · Updated Nov 6, 2024

Stack-based buffer overflow in Cisco Discovery Protocol in Cisco NX-OS Software allows attackers to execute root code or reload devices. The protocol process improperly validates specific values in a received Cisco Discovery Protocol message and writes beyond a stack buffer. Exploitation requires a crafted Layer 2 packet from the same broadcast domain; successful attacks gain root execution or repeatedly crash the process until the device reloads.

CVSS severity8.8
High
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in Cisco Discovery Protocol in Cisco NX-OS Software allows attackers to execute root code or reload devices. The protocol process improperly validates specific values in a received Cisco Discovery Protocol message and writes beyond a stack buffer. Exploitation requires a crafted Layer 2 packet from the same broadcast domain; successful attacks gain root execution or repeatedly crash the process until the device reloads.

The record

CVE
CVE-2022-20824
Published
Aug 25, 2022
Updated
Nov 6, 2024
Vendor
ClamAV
Product
Cisco NX-OS Software
Classifications
CWE-787, CWE-121, T1210, T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 25, 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

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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 vectoradjacent
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco NX-OS Softwareversion=n/a

Published CVSS scores

8.8Cisco Systems, Inc.CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:X/RL:X/RC:X
8.8NISTCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
CWE-121Stack-based Buffer Overflow
T1210Exploitation of Remote Services
T1499.004Application or System Exploitation

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

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Your stack

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