Is CVE-2021-3502 in the CISA KEV catalog?

No. CVE-2021-3502 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-3502?

CVE-2021-3502 has a CVSS v3 base score of 5.5 (MEDIUM).

What is the EPSS score for CVE-2021-3502?

CVE-2021-3502 has an EPSS score of 0.37% (29th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-3502?

Upgrade avahi on debian 11 to 0.8-5+deb11u1 or later. Fixes are available for 50 affected products.

CVE & CISA-KEV Catalog

CVE-2021-3502

MEDIUM

5.5

CVSS v3

NVD

Description

A flaw was found in avahi 0.8-5. A reachable assertion is present in avahi_s_host_name_resolver_start function allowing a local attacker to crash the avahi service by requesting hostname resolutions through the avahi socket or dbus methods for invalid hostnames. The highest threat from this vulnerability is to the service availability.

CWE-617

How to fix

Remediation Available

avahiDebian

Fixed in:0.8-5+deb11u1CVE-2021-3502

Fixed in:0.8-6CVE-2021-3502

avahiRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahiRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-autoipd-debuginfoRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-autoipd-debuginfoRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-compat-howlRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-compat-howlRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-compat-howl-debuginfoRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-compat-howl-debuginfoRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-compat-howl-develRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-compat-howl-develRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-compat-libdns_sdRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-compat-libdns_sdRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-compat-libdns_sd-debuginfoRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-compat-libdns_sd-debuginfoRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-compat-libdns_sd-develRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-compat-libdns_sd-develRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-debuginfoRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-debuginfoRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-debugsourceRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-debugsourceRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-develRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-develRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-dnsconfd-debuginfoRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-dnsconfd-debuginfoRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-glibRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-glibRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-glib-debuginfoRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-glib-debuginfoRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-glib-develRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-glib-develRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-gobject-debuginfoRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-gobject-debuginfoRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-libsRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-libsRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-libs-debuginfoRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-libs-debuginfoRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-toolsRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-toolsRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-tools-debuginfoRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-tools-debuginfoRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-ui-debuginfoRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-ui-debuginfoRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-ui-gtk3-debuginfoRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-ui-gtk3-debuginfoRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-ui-tools-debuginfoRocky

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahi-ui-tools-debuginfoRed Hat / RHEL

Fixed in:0:0.8-15.el9RHSA-2023:6707

avahiUbuntu

Fixed in:0.7-3.1ubuntu1.3USN-5008-1

Fixed in:0.7-4ubuntu7.1USN-5008-1

avahi-daemonUbuntu

Fixed in:0.7-3.1ubuntu1.3USN-5008-1

Fixed in:0.7-4ubuntu7.1USN-5008-1

libavahi-core7Ubuntu

Fixed in:0.7-3.1ubuntu1.3USN-5008-1

Fixed in:0.7-4ubuntu7.1USN-5008-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorLocal

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Exploit Intelligence

0.37%probability of exploitation in 30 days

29thpercentile

Low risk: more likely to be exploited than 29% of all known CVEs.

References

Patch1

bugzilla.redhat.com

Exploit1

github.com

Related Vulnerabilities

Other CWE-617 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2020-8617	High	7.5	93%	-	Fix
CVE-2020-36222	High	7.5	78%	-	Fix
CVE-2006-5779	High	7.5	75%	-	Fix
CVE-2021-27212	High	7.5	64%	-	Fix
CVE-2018-5740	High	7.5	59%	-	Fix
CVE-2023-28425	Medium	5.5	55%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.