CVE-2023-38473VulnerabilityPublished 2 Nov 2023Updated 3 Nov 2025

CVE-2023-38473: avahi · Reachable Assertion

Affects avahiSource CVE Database V5

Not known to be exploited · CVSS 6.2 Medium.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

6.2Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Local
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 2 Nov 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

Organizations should monitor vendor advisories and apply patches promptly once available to address CVE-2023-38473. Until patches are released, mitigating the risk involves restricting local access to systems running Avahi, such as enforcing strict user permissions and network segmentation to limit who can interact with vulnerable hosts. Disabling or uninstalling Avahi on systems where it is not essential can reduce the attack surface. For critical systems, consider implementing monitoring to detect Avahi service crashes or abnormal behavior indicative of exploitation attempts. Network administrators should audit and harden local access controls, including physical security and user account management, to prevent unauthorized local access. Additionally, organizations can explore containerization or sandboxing of Avahi services to limit the impact of potential crashes. Documenting and rehearsing incident response plans for service outages related to Avahi will improve resilience. Collaboration with Linux distribution maintainers and security communities can provide early access to patches or workarounds.

Description

A vulnerability was found in Avahi. A reachable assertion exists in the avahi_alternative_host_name() function.

Impact

For European organizations, the primary impact is a denial of service on systems running Avahi, which could disrupt local network service discovery and related operations. This may affect environments with Linux desktops, servers, or embedded devices that rely on Avahi for zero-configuration networking, such as office networks, IoT deployments, or industrial control systems. Service disruptions could lead to operational inefficiencies, especially in environments where network service discovery is critical for automated workflows or device communication. While the vulnerability does not allow data breaches or system compromise, repeated or targeted local exploitation could degrade network reliability and availability. Organizations with remote or distributed workforces using Linux systems may face increased risk if local access controls are weak. The absence of known exploits reduces immediate risk but does not eliminate the need for vigilance. The impact is more pronounced in sectors relying heavily on Linux infrastructure and Avahi, including telecommunications, manufacturing, and research institutions across Europe.

References

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 3 Nov 2025, 23:38 UTC

Technical details

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