CVE-2025-30193 | Denial of service via crafted TCP exchange

In some circumstances, when DNSdist is configured to allow an unlimited number of queries on a single, incoming TCP connection from a client, an attacker can cause a denial of service by crafting a TCP exchange that triggers an exhaustion of the stack and a crash of DNSdist, causing a denial of service. The remedy is: upgrade to the patched 1.9.10 version. A workaround is to restrict the maximum number of queries on incoming TCP connections to a safe value, like 50, via the setMaxTCPQueriesPerConnection setting. We would like to thank Renaud Allard for bringing this issue to our attention.

Published: 2025-05-20 Last update: 2026-04-15 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-30193 is rated Moderate Risk (42.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.15%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-30193

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-16 0.07% 0.15% +0.09%
2 2025-11-21 0.23% 0.07% -0.17%
3 2025-11-18 — 0.23% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-30193

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2025-30193

OS Trackers for CVE-2025-30193

vendor priority summary link
alpine high CVE-2025-30193: 1 source package rows (dnsdist); 3 state rows across 3 repos (3.21-community, 3.22-community, edge-community); fixed 3, open 0. https://security.alpinelinux.org/vuln/CVE-2025-30193
debian end-of-life CVE-2025-30193 end-of-life priority: Debian including 1 source packages (dnsdist), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 3, open 2. https://security-tracker.debian.org/tracker/CVE-2025-30193
suse high — https://www.suse.com/security/cve/CVE-2025-30193/
ubuntu medium CVE-2025-30193 medium priority: Ubuntu including 1 source packages (dnsdist), 9 status rows across 9 suites (bionic, focal, jammy, noble, oracular, plucky, questing, upstream, xenial): not-affected 4, released 3, ignored 2. https://ubuntu.com/security/CVE-2025-30193

Affected software / configurations for CVE-2025-30193

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2025-30193

cvelogic Threat Intelligence