Submit #673138: dnsmasq dnsmasq v2.73rc6 Heap-based Buffer Overflowinfo

Titlednsmasq dnsmasq v2.73rc6 Heap-based Buffer Overflow
DescriptionA heap buffer overflow exists in dnsmasq v2.73rc6 when parsing DHCP option hexadecimal values. The vulnerability is in `parse_hex()` (src/util.c) which can write past the end of the allocated buffer (callers allocate based on a computed byte count). A crafted DHCP option in `dnsmasq.conf` causes `parse_hex()` to overflow the heap buffer during configuration parsing, resulting in a crash and potential memory corruption. Reproduce by replacing `dnsmasq.conf` with the supplied config and starting dnsmasq; an ASan build produces a reliable crash referencing `parse_hex`.
Source⚠️ https://shimo.im/docs/1d3aMVMmNmiLjg3g/
User
 zh_vul (UID 91488)
Submission10/11/2025 05:30 (8 months ago)
Moderation10/25/2025 08:22 (14 days later)
StatusAccepted
VulDB entry329868 [dnsmasq up to 2.73rc6 Config File src/util.c parse_hex i heap-based overflow]
Points20

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