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CVE-2026-30871

OpenWrt Project has Stack-based Buffer Overflow in DNS PTR Query

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 24.10.6, 25.12.1
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: yes
  • Technical impact: total

Summary

OpenWrt Project is a Linux operating system targeting embedded devices. In versions prior to 24.10.6 and 25.12.1, the mdns daemon has a Stack-based Buffer Overflow vulnerability in the parse_question function. The issue is triggered by PTR queries for reverse DNS domains (.in-addr.arpa and .ip6.arpa). DNS packets received on UDP port 5353 are expanded by dn_expand into an 8096-byte global buffer (name_buffer), which is then copied via an unbounded strcpy into a fixed 256-byte stack buffer when handling TYPE_PTR queries. The overflow is possible because dn_expand converts non-printable ASCII bytes (e.g., 0x01) into multi-character octal representations (e.g., \001), significantly inflating the expanded name beyond the stack buffer's capacity. A crafted DNS packet can exploit this expansion behavior to overflow the stack buffer, making the vulnerability reachable through normal multicast DNS packet processing. This issue has been fixed in versions 24.10.6 and 25.12.1.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: yes · Technical impact: total

  3. Record last updated

Affected versions

  • openwrt openwrt

    fixed in 24.10.6; From 25.12.0-rc1 · fixed in 25.12.1

References 3

GitHub · openwrt/openwrt