The Cybersecurity and Infrastructure Security Agency (CISA) has warned that attackers are actively exploring the very vulnerable Linux flaw known as PwnKit in the wild.
The CISA also gave all Federal Civilian Executive Branch Agencies (FCEB) until July 18 to patch their Linux servers against PwnKit and block exploitation attempts. Although addressed to federal agencies, the CISA asked public and private sector organizations to ensure that the vulnerability is patched.
The bug, which is tracked as CVE-2021-403, is a memory corruption flaw that can be exploited by unauthenticated users to gain root privileges on Linux systems by default configurations. The vulnerability was found in the Polkit’s pkexec component used by all major distributions (including Ubuntu, Debian, Fedora, and CentOS).
The CISA encouraged government agencies and private sector organizations to use Microsoft Exchange to validate the transition from Basic Auth legacy authentication methods to Modern Auth alternatives.
FCEB agencies have also been advised to block Basic auth after migrating to Modern Auth as it makes it harder for threat actors to extract password and credentials fillings.
The sources for this piece include an article in BleepingComputer.
