Directory-existence disclosure via parent-directory symlink race
Published Jan 12, 2021 · Updated Aug 3, 2024
Information disclosure in Sudo before 1.9.5 allows local users to determine whether arbitrary privileged directories exist. When a target file is absent, sudo_edit.c uses stat() on its parent path, letting a user race a controlled directory into a symlink and infer the link target from sudoedit's response. Exploitation requires permission to run sudoedit for a file beneath the controlled directory and winning the race; it reveals existence only and cannot read or write the target.
Summary
What happened
Information disclosure in Sudo before 1.9.5 allows local users to determine whether arbitrary privileged directories exist. When a target file is absent, sudo_edit.c uses stat() on its parent path, letting a user race a controlled directory into a symlink and infer the link target from sudoedit's response. Exploitation requires permission to run sudoedit for a file beneath the controlled directory and winning the race; it reveals existence only and cannot read or write the target.
The record
- CVE
- CVE-2021-23239
- Published
- Jan 12, 2021
- Updated
- Aug 3, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-59, T1083
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jan 12, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo