CVE-2024-29069 snapd will follow archived symlinks when unpacking a filesystem

2024-07-2519:39:41

CWE-610

canonical

github.com

snapd

filesystem

symbolic links

security vulnerability

CVSS3

4.8

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality Impact

LOW

Integrity Impact

LOW

Availability Impact

LOW

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

AI Score

6.8

Confidence

Low

SSVC

Exploitation

none

Automatable

Technical Impact

partial

JSON

In snapd versions prior to 2.62, snapd failed to properly check the
destination of symbolic links when extracting a snap. The snap format
is a squashfs file-system image and so can contain symbolic links and
other file types. Various file entries within the snap squashfs image
(such as icons and desktop files etc) are directly read by snapd when
it is extracted. An attacker who could convince a user to install a
malicious snap which contained symbolic links at these paths could then
cause snapd to write out the contents of the symbolic link destination
into a world-readable directory. This in-turn could allow an unprivileged
user to gain access to privileged information.

CNA Affected

[
  {
    "repo": "https://github.com/snapcore/snapd/",
    "vendor": "Canonical",
    "modules": [
      "squashfs"
    ],
    "product": "snapd",
    "versions": [
      {
        "status": "affected",
        "version": "0",
        "lessThan": "2.62",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "Linux"
    ],
    "packageName": "snapd",
    "programFiles": [
      "snap/container.go",
      "snap/snapdir/snapdir.go",
      "snap/squashfs/squashfs.go"
    ],
    "defaultStatus": "unaffected"
  }
]