ACSC alerts on critical Atlassian Confluence bug

The Australian government's cyber security centre has issued a high status alert to warn users of Atlassian's Confluence that the corporate wiki software contains a serious vulnerability that allows attackers to execute code remotely, with no authentication required.

Atlassian said the bug is an Object-Graph Navigation Language (OGNL) code injection vulnerability, affecting self-hosted Confluence Server and Data Centre versions, but not the Cloud variant.

Proof-of-concept code has been published for the flaw, which was discovered by security researcher Benny Jacob.

ACSC and security researchers are warning that attackers are looking for, and attempting to exploit, vulnerable Confluence instances currently.

We've detected mass scanning and exploit activity from hosts in ���� ���� ���� �������� ���� ���� targeting Atlassian Confluence servers vulnerable to remote code execution (https://t.co/GExSx8puLm).

Query our API for "tags=CVE-2021-26084" for full payload and source IPs. #threatintel

— Bad Packets (@bad_packets) September 1, 2021

"Australian organisations who self-host Atlassian Confluence should identify any internet-facing instances of Confluence as a priority," ACSC said.

"Internal instances of Confluence should also be identified."

Confluence customers are advised to upgrade to versions 6.13.23, 7.11.6, 7.12.5, 7.13 or 7.4.11 in which the vulnerability is patched.