Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2025-59529— simple protocol server ignores accepts unlimited connections and logs failures without limit

Quick assessment

Affected
avahi avahi
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Avahi是Avahi开源的一套用于Linux的本地服务发现工具。 Avahi 0.9-rc2及之前版本存在资源管理错误漏洞，该漏洞源于无条件接受连接且未检查客户端限制，可能导致本地拒绝服务。

CVSS 5.5 · Medium EPSS 0.18% · P7
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2025-59529

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
simple protocol server ignores accepts unlimited connections and logs failures without limit
Source: CVE Program / CVE List V5
Vulnerability Description
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-rc2, 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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
未加控制的资源消耗(资源穷尽)
Source: CVE Program / CVE List V5
Vulnerability Title
Avahi 资源管理错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Avahi是Avahi开源的一套用于Linux的本地服务发现工具。 Avahi 0.9-rc2及之前版本存在资源管理错误漏洞，该漏洞源于无条件接受连接且未检查客户端限制，可能导致本地拒绝服务。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
avahi avahi <= 0.9-rc2 -

II. Public POCs for CVE-2025-59529

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2025-59529

请登录查看更多情报信息。

Patches & Fixes for CVE-2025-59529 (1)

Vendor Advisories for CVE-2025-59529 (1)

Security Blog Posts for CVE-2025-59529 (1)

IV. Related Vulnerabilities

Same product: avahi
Same vendor: avahi
Same weakness: CWE-400

V. Comments for CVE-2025-59529

No comments yet

Leave a comment