Code execution via signed ARMv7 length comparisons
Published Apr 1, 2020 · Updated Feb 13, 2026
Integer underflow in GNU glibc 2.30.9000 on ARMv7 allows attackers to corrupt memory or execute code through a crafted memcpy length. The ARMv7 assembly compares the unsigned size_t length with signed branch conditions, so wrapped values take short-copy paths and write corrupted data instead of faulting. Exploitation requires a linked program to pass an attacker-controlled underflowed length; successful abuse corrupts memory, crashes the process, or executes code in its context.
Summary
What happened
Integer underflow in GNU glibc 2.30.9000 on ARMv7 allows attackers to corrupt memory or execute code through a crafted memcpy length. The ARMv7 assembly compares the unsigned size_t length with signed branch conditions, so wrapped values take short-copy paths and write corrupted data instead of faulting. Exploitation requires a linked program to pass an attacker-controlled underflowed length; successful abuse corrupts memory, crashes the process, or executes code in its context.
The record
- CVE
- CVE-2020-6096
- Published
- Apr 1, 2020
- Updated
- Feb 13, 2026
- Vendor
- GNU
- Product
- GNU C Library (glibc)
- Classifications
- CWE-195
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 1, 2020CVE publishedPublication date reported by the CVE source.
- Feb 13, 2026Record 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=2.30.9000
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 ARMv7 memcpy test programproof 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