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TI-2021-02431 Aliases CVE-2021-3468GHSA-43rm-fv4g-cmj8

Infinite loop in avahi

Priority LOW 25CWE-835Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 12 fixed, 2 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-835.

Summary

A flaw was found in avahi in versions 0.6 up to 0.8. The event used to signal the termination of the client connection on the avahi Unix socket is not correctly handled in the client_work function, allowing a local attacker to trigger an infinite loop. The highest threat from this vulnerability is to the availability of the avahi service, which becomes unresponsive after this flaw is triggered.

Why it matters now

EPSS 0.00439 38th percentileScored 2026-11-07
Fix Partial Red Hat: 4 advisoriesRed Hat: 12 fixed, 2 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
—avahiAll avahi versions 0.6 up to 0.8—No fix listedCNA
  • avahi Vendor— Affected All avahi versions 0.6 up to 0.8 Fixed in — No fix listed CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:avahi:avahi:*:*:*:*:*:*:*:*0.6 – 0.8Vulnerableavahi
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*9.0VulnerableDebian
  • cpe:2.3:a:avahi:avahi:*:*:*:*:*:*:*:* Versions 0.6 – 0.8 Vulnerable ·avahi
  • cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian

Remediation

Red Hat 4 advisories

  • RHSA-2024:0576 Released 2024-01-30 · Red Hat rating Moderate
    avahi security update
    • Red Hat CodeReady Linux Builder EUS (v.8.8) avahi-compat-howl-0.7-20.el8_8.4, avahi-compat-howl-devel-0.7-20.el8_8.4, avahi-compat-libdns_sd-0.7-20.el8_8.4 +6
    • Red Hat Enterprise Linux AppStream EUS (v.8.8) avahi-ui-gtk3-0.7-20.el8_8.4
    • Red Hat Enterprise Linux BaseOS EUS (v.8.8) avahi-0.7-20.el8_8.4, avahi-autoipd-0.7-20.el8_8.4, avahi-glib-0.7-20.el8_8.4 +3
  • RHSA-2024:0418 Released 2024-01-25 · Red Hat rating Moderate
    avahi security update
    • Red Hat CodeReady Linux Builder EUS (v.8.6) avahi-compat-howl-0.7-20.el8_6.3, avahi-compat-howl-devel-0.7-20.el8_6.3, avahi-compat-libdns_sd-0.7-20.el8_6.3 +6
    • Red Hat Enterprise Linux AppStream EUS (v.8.6) avahi-ui-gtk3-0.7-20.el8_6.3
    • Red Hat Enterprise Linux BaseOS EUS (v.8.6) avahi-0.7-20.el8_6.3, avahi-autoipd-0.7-20.el8_6.3, avahi-glib-0.7-20.el8_6.3 +3
  • RHSA-2023:7836 Released 2023-12-14 · Red Hat rating Moderate
    avahi security update
    • Red Hat CodeReady Linux Builder (v. 8) avahi-compat-howl-0.7-21.el8_9.1, avahi-compat-howl-devel-0.7-21.el8_9.1, avahi-compat-libdns_sd-0.7-21.el8_9.1 +6
    • Red Hat Enterprise Linux AppStream (v. 8) avahi-tools-0.7-21.el8_9.1, avahi-ui-gtk3-0.7-21.el8_9.1
    • Red Hat Enterprise Linux BaseOS (v. 8) avahi-0.7-21.el8_9.1, avahi-autoipd-0.7-21.el8_9.1, avahi-glib-0.7-21.el8_9.1 +3
Show 1 more Red Hat advisories
  • RHSA-2023:6707 Released 2023-11-07 · Red Hat rating Moderate
    avahi security update
    • Red Hat CodeReady Linux Builder (v. 9) avahi-compat-howl-0.8-15.el9, avahi-compat-howl-devel-0.8-15.el9, avahi-compat-libdns_sd-0.8-15.el9 +3
    • Red Hat Enterprise Linux AppStream (v. 9) avahi-glib-0.8-15.el9, avahi-tools-0.8-15.el9
    • Red Hat Enterprise Linux BaseOS (v. 9) avahi-0.8-15.el9, avahi-libs-0.8-15.el9

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat CodeReady Linux Builder (v. 8)Fixed RHSA-2023:7836
Red Hat CodeReady Linux Builder (v. 9)Fixed RHSA-2023:6707
Red Hat CodeReady Linux Builder EUS (v.8.6)Fixed RHSA-2024:0418
Red Hat CodeReady Linux Builder EUS (v.8.8)Fixed RHSA-2024:0576
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2023:7836
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2023:6707
Red Hat Enterprise Linux AppStream EUS (v.8.6)Fixed RHSA-2024:0418
Red Hat Enterprise Linux AppStream EUS (v.8.8)Fixed RHSA-2024:0576
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2023:7836
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2023:6707
Red Hat Enterprise Linux BaseOS EUS (v.8.6)Fixed RHSA-2024:0418
Red Hat Enterprise Linux BaseOS EUS (v.8.8)Fixed RHSA-2024:0576

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-3468
  2. 2026-10-03 Alias added: GHSA-43rm-fv4g-cmj8

References

Advisory 1

Other 2

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences