MikroTik RouterOS Stack-Based Buffer Overflow Vulnerability

[ Why it matters ]Priority signals

• Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2022-09-08
• EPSS: 61% chance of exploitation in the next 30 days (higher than 99% of CVEs)
• Critical severity: CVSS 9.8

[ Description ]Official description

A buffer overflow was found in the MikroTik RouterOS SMB service when processing NetBIOS session request messages. Remote attackers with access to the service can exploit this vulnerability and gain code execution on the system. The overflow occurs before authentication takes place, so it is possible for an unauthenticated remote attacker to exploit it. All architectures and all devices running RouterOS before versions 6.41.3/6.42rc27 are vulnerable.

CISA: In MikroTik RouterOS, a stack-based buffer overflow occurs when processing NetBIOS session request messages. Remote attackers with access to the service can exploit this vulnerability and gain code execution on the system.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 29 Sep 2022): Apply updates per vendor instructions.

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References

• seclists.org/fulldisclosure/2018/Mar/38ExploitMailing ListThird Party Advisory
• www.securityfocus.com/bid/103427Third Party AdvisoryVDB Entry
• www.coresecurity.com/advisories/mikrotik-routeros-smb-buffer-overflowExploitThird Party Advisory
• www.exploit-db.com/exploits/44290ExploitThird Party AdvisoryVDB Entry
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource