OneDev: RCE through absolute-path symlink following allows low-privileged users to overwrite arbitrary server via TarUtils.untar

OneDev is a Git server with CI/CD, kanban, and packages. In versions 15.0.6 and below, TarUtils.untar() creates symbolic links verbatim from TAR entry getLinkName() without validating whether the target is an absolute path. A subsequent file entry in the same archive traverses the symlink, writing to arbitrary server-side locations. This is exploitable by any authenticated user with CI Job write access — no admin interaction required. This is an incomplete fix bypass of CVE-2021-21251 (GHSA-2w6j-wc8c-9mq2): that patch blocked .. path segments but did not address absolute symlink targets. This issue has been fixed in version 15.0.7.