Application interruption via unchecked buffer-size addition
Published Jan 31, 2024 · Updated Jul 14, 2026
Integer overflow in glibc 2.37 through 2.38 allows remote attackers to interrupt applications through an oversized syslog message. The __vsyslog_internal function adds two integer lengths without checking whether the sum overflows, producing an incorrect message-buffer size. A reachable application must pass a very long message to syslog or vsyslog; the documented consequence is undefined behavior with availability impact.
Summary
What happened
Integer overflow in glibc 2.37 through 2.38 allows remote attackers to interrupt applications through an oversized syslog message. The __vsyslog_internal function adds two integer lengths without checking whether the sum overflows, producing an incorrect message-buffer size. A reachable application must pass a very long message to syslog or vsyslog; the documented consequence is undefined behavior with availability impact.
The record
- CVE
- CVE-2023-6780
- Published
- Jan 31, 2024
- Updated
- Jul 14, 2026
- Vendor
- Fedora Project
- Product
- Fedora Linux
- Classifications
- CWE-131, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 31, 2024CVE publishedPublication date reported by the CVE source.
- Jul 14, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
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
- Qualys syslog integer-overflow proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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