openSUSE Backports SLE-15-SP3: Improper Link Resolution Before File Access
CVE-2022-21944 is a high-severity improper link resolution before file access vulnerability in openSUSE Backports SLE-15-SP3 from openSUSE, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists version 4.9.0 as the first without the flaw, so updating openSUSE Backports SLE-15-SP3 to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.29% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update openSUSE Backports SLE-15-SP3 to 4.9.0 or a later version.
- Update Factory to 4.9.0-9.1 or a later version.
- Read the advisory on bugzilla.suse.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| openSUSE | openSUSE Backports SLE-15-SP3 | watchman up to, but not including, 4.9.0 | 4.9.0 |
| openSUSE | Factory | watchman up to, but not including, 4.9.0-9.1 | 4.9.0-9.1 |
| openSUSE | Factory Watchman | 4.9.1 and earlier | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA (suse.de) |
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 2.0 | 7.2 | High | NVD |
Official description
A UNIX Symbolic Link (Symlink) Following vulnerability in the systemd service file for watchman of openSUSE Backports SLE-15-SP3, Factory allows local attackers to escalate to root. This issue affects: openSUSE Backports SLE-15-SP3 watchman versions prior to 4.9.0. openSUSE Factory watchman versions prior to 4.9.0-9.1.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Link Resolution Before File Access
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.
How developers prevent this class of flaw
- Follow the principle of least privilege when assigning access rights to entities in a software system. Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.
More Improper Link Resolution Before File Access vulnerabilities (CWE-59)
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Advisories
- bugzilla.suse.com/show_bug.cgi?id=1194470Issue Tracking
Recent Improper Link Resolution Before File Access vulnerabilities
- 7.1 High severity
- 6.9 Medium severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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