The flaw is a stack-based buffer overflow in MAWK 1.3.3-17 and earlier versions, allowing attackers to exploit inadequately checked user input. This vulnerability can be triggered by crafted data that overflows the stack buffer, enabling a return-oriented programming chain that launches a shell with the application’s privileges. The primary consequence is the ability to execute arbitrary code with the rights of the running service, compromising confidentiality, integrity, and availability of the affected system.

MAWK, a publicly available scripting language, is affected in versions 1.3.3-17 and all preceding releases. The flaw applies to installations of the MAWK package distributed by the Invisible Island project. Any machine running these versions is vulnerable.

The CVSS base score of 9.3 classifies this modification as high severity, and the EPSS score of less than 1% indicates a low estimated exploitation probability but not zero. The vulnerability is listed as not part of the CISA KEV catalog. Exfiltration relies on externally supplied input, which suggests that an attacker must be able to supply data to the MAWK interpreter, such as via scripts or data files. If successful, remote code execution is possible.