TL;DR

Cisco Snort versions before 3.3.1 have an out-of-bounds read vulnerability in _bnfa_search_csparse_nfa function, allowing for info disclosure.

What happened

["Out-of-bounds read in Cisco Snort's _bnfa_search_csparse_nfa function", 'Can be exploited remotely without authentication']

Why it matters for ops

['Exploit may result in unauthorized access to sensitive information', 'No user interaction required to trigger the vulnerability']

Mitigation

  • Update to Cisco Snort version 3.3.1 or later
  • Apply network segmentation and restrictive firewall rules to limit access to vulnerable systems

Action items

  • Deploy updates for Cisco Snort to address CVE-2026-20027
  • Monitor network traffic for signs of exploitation attempts

Detection IOCs

  • Unexpected read errors or crashes involving _bnfa_search_csparse_nfa function
  • Network traffic anomalies from unauthenticated sources targeting affected Cisco Snort installations

Source link

http://www.zerodayinitiative.com/advisories/ZDI-26-045/