CVE-2021-29693

Service interruption via undisclosed lpd flaw

Published Jun 28, 2021 · Updated Sep 17, 2024

Denial of service in the lpd daemon in IBM AIX 7.1, 7.2, and VIOS 3.1 allows local users with elevated group privileges to interrupt service. IBM has not published the operation within lpd that mishandles attacker-controlled input or the specific failure mode. Exploitation requires elevated group privileges on the host and affects availability only; no data disclosure or modification is reported.

CVSS severity4.9
Medium
EPSS probability0.65%
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 the lpd daemon in IBM AIX 7.1, 7.2, and VIOS 3.1 allows local users with elevated group privileges to interrupt service. IBM has not published the operation within lpd that mishandles attacker-controlled input or the specific failure mode. Exploitation requires elevated group privileges on the host and affects availability only; no data disclosure or modification is reported.

The record

CVE
CVE-2021-29693
Published
Jun 28, 2021
Updated
Sep 17, 2024
Vendor
IBM
Product
AIX
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 28, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 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=7.1
  2. Affected versionversion=7.2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

IBM · AIXversion=7.1; version=7.2
IBM · PowerVM Virtual I/O Serverversion=3.1

Published CVSS scores

4.9IBM CorporationCVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
4.4NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
2.1NIST NVDAV:L/AC:L/Au:N/C:N/I:N/A:P

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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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

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