Microsoft security update for CVE-2025-59529
🔗 CVE IDs covered (1)
📋 Microsoft's advisory
EchelonGraph does not copy Microsoft's advisory page: its FAQ and remediation text are not shown here. Read the advisory on https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-59529. This page also shows what EchelonGraph holds for CVE-2025-59529, with the description from its CVE record, which the CVE Numbering Authority that assigned the CVE wrote: for a CVE Microsoft assigned, often in the words of Microsoft's own advisory.
🎯 Affected products9
- azl3 avahi 0.8-5 on Azure Linux 3.0
- azl3 avahi 0.8-6 on Azure Linux 3.0
- azl3 avahi 0.8-7 on Azure Linux 3.0
- azl3 avahi 0.8-8 on Azure Linux 3.0
- azl3 avahi 0.8-9 on Azure Linux 3.0
- cbl2 avahi 0.8-4 on CBL Mariner 2.0
- cbl2 avahi 0.8-5
- cbl2 avahi 0.8-5 on CBL Mariner 2.0
- cbl2 avahi 0.8-5 on CBL-Mariner 2.0
✅ Updates Microsoft lists: 1 update
1 row: one per KB article or update, update type and fixed build. Their details are on Microsoft's advisory.
| KB article | Update | Fixed build |
|---|---|---|
| — | Security Update | — |
🧭 EchelonGraph on CVE-2025-59529
- EchelonGraph score
- 5.5 MEDIUM
- CISA KEV
- Not listed
- Fix status
- A fix is available — apply it.
Description from the CVE record (CVE.org), as published by its numbering authority
Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. In versions up to and including 0.9-rc5, the simple protocol server ignores the documented client limit and accepts unlimited connections, allowing for easy local DoS. Although `CLIENTS_MAX` is defined, `server_work()` unconditionally `accept()`s and `client_new()` always appends the new client and increments `n_clients`. There is no check against the limit. When client cannot be accepted as a result of maximal socket number of avahi-daemon, it logs unconditionally error per each connection. Unprivileged local users can exhaust daemon memory and file descriptors, causing a denial of service system-wide for mDNS/DNS-SD. Exhausting local file descriptors causes increased system load caused by logging errors of each of request. Overloading prevents glibc calls using nss-mdns plugins to resolve `*.local.` names and link-local addresses. As of time of publication, no known patched versions are available, but a candidate fix is available in pull request 808, and some workarounds are available. Simple clients are offered for nss-mdns package functionality. It is not possible to disable the unix socket `/run/avahi-daemon/socket`, but resolution requests received via DBus are not affected directly. Tools avahi-resolve, avahi-resolve-address and avahi-resolve-host-name are not affected, they use DBus interface. It is possible to change permissions of unix socket after avahi-daemon is started. But avahi-daemon does not provide any configuration for it. Additional access restrictions like SELinux can also prevent unwanted tools to access the socket and keep resolution working for trusted users.
Published by GitHub, Inc., the CVE Numbering Authority that assigned CVE-2025-59529, in its CVE record at CVE.org; reused under the CVE Program's Terms of Use (its licence and MITRE's copyright notice are in our Terms of Service).