macOS: Improper Link Resolution Before File Access
CVE-2022-26704 is a high-severity improper link resolution before file access vulnerability in macOS from Apple, 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 unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists version 12.4 as the first without the flaw, so updating macOS to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.04% chance of exploitation within 30 days, higher than 64% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update macOS to 12.4 or a later version.
- Update Mac OS X to 10.15.7 or a later version.
- Read the advisory on support.apple.com for workarounds and exact fixed builds.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apple | macOS | before 12.4 | 12.4 |
| Apple | Mac OS X | 10.15 up to, but not including, 10.15.7; 10.15.7 | 10.15.7 |
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
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- 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:N/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 2.0 | 6.8 | Medium | NVD |
Official description
A validation issue existed in the handling of symlinks and was addressed with improved validation of symlinks. This issue is fixed in macOS Monterey 12.4. An app may be able to gain elevated privileges.
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
Third-party and government advisories
- seclists.org/fulldisclosure/2022/Jul/13Mailing List, Third Party Advisory
- seclists.org/fulldisclosure/2022/Jul/14Mailing List, Third Party Advisory
- github.com/mandiant/Vulnerability-Disclosures/blob/master/2022/MNDT-2022-0032/MNDT-2022-0032.mdTechnical Description, Third Party Advisory
Other references
- support.apple.com/kb/HT213343Mailing List
Other vulnerabilities in macOS
- 8.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
Recent Improper Link Resolution Before File Access vulnerabilities
- 7.0 High severity
- 7.8 High severity
- 7.8 High severity
- 7.2 High severity
- 7.8 High severity
- 7.8 High severity
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