This is an automated email from the git hooks/post-receive script. It was generated because a ref change was pushed to the repository containing the project "The official pacman repository". The branch, master has been updated via d197d8ab82cf10650487518fb968067897a12775 (commit) from adb961a88e6644d5edb16cfcb5dbd1f02e4a1781 (commit) Those revisions listed above that are new to this repository have not appeared on any other notification email; so we list those revisions in full, below. - Log ----------------------------------------------------------------- commit d197d8ab82cf10650487518fb968067897a12775 Author: Andrew Gregory <andrew.gregory.8@gmail.com> Date: Fri Mar 1 11:23:20 2019 +1000 Sanitize file name received from Content-Disposition header When installing a remote package with "pacman -U <url>", pacman renames the downloaded package file to match the name given in the Content-Disposition header. However, pacman does not sanitize this name, which may contain slashes, before calling rename(). A malicious server (or a network MitM if downloading over HTTP) can send a content-disposition header to make pacman place the file anywhere in the filesystem, potentially leading to arbitrary root code execution. Notably, this bypasses pacman's package signature checking. For example, a malicious package-hosting server (or a network man-in-the-middle, if downloading over HTTP) could serve the following header: Content-Disposition: filename=../../../../../../usr/share/libalpm/hooks/evil.hook and pacman would move the downloaded file to /usr/share/libalpm/hooks/evil.hook. This invocation of "pacman -U" would later fail, unable to find the downloaded package in the cache directory, but the hook file would remain in place. The commands in the malicious hook would then be run (as root) the next time any package is installed. Discovered-by: Adam Suhl <asuhl@mit.edu> Signed-off-by: Allan McRae <allan@archlinux.org> ----------------------------------------------------------------------- Summary of changes: lib/libalpm/dload.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) hooks/post-receive -- The official pacman repository