Bug 2406461 (CVE-2025-12199)

Summary: CVE-2025-12199 dnsmasq: dnsmasq Config File network.c check_servers null pointer dereference
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: low    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A null pointer dereference vulnerability exists in dnsmasq, within the function check_servers() in src/network.c. When dnsmasq attempts to log upstream servers during startup, a malformed or inconsistent configuration may cause the SERV_HAS_DOMAIN flag to be set while serv->domain is NULL. This results in a call to strlen(serv->domain), triggering a segmentation fault and crashing the service. The issue leads to a Denial of Service (DoS) condition, preventing dnsmasq from starting properly.
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Description OSIDB Bzimport 2025-10-27 02:01:15 UTC 
A vulnerability was found in dnsmasq up to 2.73rc6. Affected by this vulnerability is the function check_servers of the file src/network.c of the component Config File Handler. The manipulation results in null pointer dereference. The attack needs to be approached locally. The exploit has been made public and could be used. The vendor was contacted early about this disclosure but did not respond in any way.