Daemon crash via undersized escaped-label buffer
Published Nov 2, 2023 · Updated Nov 3, 2025
Reachable assertion in Avahi allows local users to crash avahi-daemon with a crafted hostname supplied through D-Bus. avahi_normalize_name permits only one output byte to remain before appending a label-separator dot, leaving no capacity when avahi_escape_label asserts that its output buffer is nonempty. Any local user able to submit a hostname to the daemon's D-Bus resolver API can abort the service, interrupting mDNS and DNS-SD discovery until it restarts.
Summary
What happened
Reachable assertion in Avahi allows local users to crash avahi-daemon with a crafted hostname supplied through D-Bus. avahi_normalize_name permits only one output byte to remain before appending a label-separator dot, leaving no capacity when avahi_escape_label asserts that its output buffer is nonempty. Any local user able to submit a hostname to the daemon's D-Bus resolver API can abort the service, interrupting mDNS and DNS-SD discovery until it restarts.
The record
- CVE
- CVE-2023-38470
- Published
- Nov 2, 2023
- Updated
- Nov 3, 2025
- Vendor
- Red Hat
- Product
- Red Hat Enterprise Linux 8
- Classifications
- CWE-617, T1499.004
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Nov 2, 2023CVE publishedPublication date reported by the CVE source.
- Nov 3, 2025Record 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?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
- avahi-resolve crafted-hostname reproducerproof of concept · demonstrated
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