Memory corruption via fixed-address thread stack mapping
Published Sep 29, 2022 · Updated Apr 15, 2025
Memory corruption in uClibC 0.9.33.2 and uClibC-ng 1.0.40 allows attackers to overwrite process mappings during thread creation. pthread_handle_create derives descending stack addresses, and pthread_allocate_stack passes them to mmap with MAP_FIXED, discarding overlapping mappings. Exploitation requires a path that creates many threads, especially in a 32-bit process, and can corrupt loaded libraries or application code.
Summary
What happened
Memory corruption in uClibC 0.9.33.2 and uClibC-ng 1.0.40 allows attackers to overwrite process mappings during thread creation. pthread_handle_create derives descending stack addresses, and pthread_allocate_stack passes them to mmap with MAP_FIXED, discarding overlapping mappings. Exploitation requires a path that creates many threads, especially in a 32-bit process, and can corrupt loaded libraries or application code.
The record
- CVE
- CVE-2022-29503
- Published
- Sep 29, 2022
- Updated
- Apr 15, 2025
- Vendor
- uClibc-ng
- Product
- uClibc-ng
- Classifications
- CWE-770, CWE-119
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 29, 2022CVE publishedPublication date reported by the CVE source.
- Apr 15, 2025Record 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.0.40
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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
- Cisco Talos thread-allocation trigger analysisproof of concept · demonstrated
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