The Qualys Cloud Agent included a bundled uninstall script (qagent_uninstall.sh), specific to Mac and Linux supported versions that invoked multiple system commands without using absolute paths and without sanitizing the $PATH environment. If the uninstall script is executed with elevated privileges (e.g., via sudo) in an environment where $PATH has been manipulated, an attacker with root/sudo privileges could cause malicious executables to be run in place of the intended system binaries. This behavior can be leveraged for local privilege escalation and arbitrary command execution under elevated privileges.
The product searches for critical resources using an externally-supplied search path that can point to resources that are not under the product’s direct control.
This might allow attackers to execute their own programs, access unauthorized data files, or modify configuration in unexpected ways. If the product uses a search path to locate critical resources such as programs, then an attacker could modify that search path to point to a malicious program, which the targeted product would then execute. The problem extends to any type of critical resource that the product trusts. Some of the most common variants of untrusted search path are: