Buffer overflow via oversized cpio header fields
Published Apr 30, 2021 · Updated Aug 3, 2024
Integer overflow in klibc cpio before 2.0.9 allows attackers to trigger a buffer overflow on 32-bit systems with a crafted archive. The read_in_new_ascii function accepts 32-bit c_namesize and c_filesize values but passes them to long-sized I/O operations without rejecting values above LONG_MAX. Exploitation requires cpio to process a crafted new-ASCII archive on a 32-bit host; Ubuntu notes that its initramfs use does not parse untrusted data.
Summary
What happened
Integer overflow in klibc cpio before 2.0.9 allows attackers to trigger a buffer overflow on 32-bit systems with a crafted archive. The read_in_new_ascii function accepts 32-bit c_namesize and c_filesize values but passes them to long-sized I/O operations without rejecting values above LONG_MAX. Exploitation requires cpio to process a crafted new-ASCII archive on a 32-bit host; Ubuntu notes that its initramfs use does not parse untrusted data.
The record
- CVE
- CVE-2021-31872
- Published
- Apr 30, 2021
- Updated
- Aug 3, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-190
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Apr 30, 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