CVE-2019-9686 Information

Description

pacman before 5.1.3 allows directory traversal when installing a remote package via a specified URL \pacman -U url\ due to an unsanitized file name received from a Content-Disposition header. pacman renames the downloaded package file to match the name given in this header. However pacman did 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. This occurs in curl_download_internal in lib/libalpm/dload.c.

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Reference

https://git.archlinux.org/pacman.git/commit/?h=release/5.1.x&id=1bf767234363f7ad5933af3f7ce267c123017bde https://git.archlinux.org/pacman.git/commit/?id=9702703633bec2c007730006de2aeec8587dfc84 https://git.archlinux.org/pacman.git/commit/?id=d197d8ab82cf10650487518fb968067897a12775 pacman before 5.1.3 allows directory traversal when installing a remote package via a specified URL \pacman -U url
due to an unsanitized file name received from a Content-Disposition header. pacman renames the downloaded package file to match the name given in this header. However pacman did 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. This occurs in curl_download_internal in lib/libalpm/dload.c.

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

REQUIRED

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

8.8