A security researcher says he has earned $20,000 for a high-severity GitHub Enterprise vulnerability that might have allowed an attacker to execute arbitrary commands.
GitHub Enterprise, the on-premises version of GitHub.com, is designed to make it easier for large enterprise software development teams to collaborate.
In June, Australia-based software developer and security researcher William Bowling informed GitHub via its bug bounty program that he had identified a potentially serious vulnerability. Successful exploitation may have allowed an attacker to overwrite arbitrary files with malicious content, which could have resulted in arbitrary command execution on Enterprise Server instances.
Exploitation of the vulnerability on Enterprise Server instances involved injecting malicious arguments via git command options.
While in itself this is a serious vulnerability, Bowling and GitHub’s own security team failed to find a way for it to be exploited in a real-world scenario due to a cross-site request forgery (CSRF) protection mechanism implemented by the company.
“To exploit this vulnerability, an attacker would need permission to access repositories within the GitHub Enterprise Server instance. However, due to other protections in place, we could not identify a way to actively exploit this vulnerability,” GitHub explained.
Nevertheless, GitHub assessed that this was a serious vulnerability and decided to award a $20,000 bug bounty, Bowling says. This is the highest reward GitHub is offering for high-severity flaws.
The vulnerability was patched in August with the release of GitHub Enterprise 2.21.4, which also fixes a critical remote code execution vulnerability identified in GitHub Pages.
GitHub, which is owned by Microsoft, said earlier this year that it had paid out a total of more than $1 million through its bug bounty program on HackerOne. The company announced last year that there would be no top limit on critical vulnerability rewards.