Hanno Böck, author of the project , for the vulnerability of interactive compilation interfaces that allow the processing of external code in C. When specifying an arbitrary path in the "#include" directive, the compilation error includes the content of the file that failed to compile.
For example, by substituting "#include <\/etc\/shadow>" in one of the online services, it was possible to retrieve the hashed password of the root user from the /etc/shadow file, which also indicates that the web service is running with root privileges and compiles commands under the root user (it is not ruled out that an isolated container was used for compilation, but running with root privileges in a container is also a problem). The problematic service where the issue was reproduced has not been publicly disclosed yet. Attempts to open files in the pseudo FS /proc were unsuccessful as GCC treats them as empty files, but opening files from /sys works.
Source: opennet.ru
