Sensitive-data disclosure via RSA-PSK timing
Published Nov 28, 2023 · Updated Feb 25, 2026
Timing side-channel in GnuTLS RSA-PSK key exchange allows remote attackers to infer sensitive data from TLS response-time differences. RSA-PSK ClientKeyExchange processing responds measurably differently to malformed ciphertexts than to correctly PKCS#1 v1.5-padded ciphertexts. The attack requires repeated network observations and RSA-PSK use; the documented impact is indirect confidentiality disclosure without integrity or availability effects.
Summary
What happened
Timing side-channel in GnuTLS RSA-PSK key exchange allows remote attackers to infer sensitive data from TLS response-time differences. RSA-PSK ClientKeyExchange processing responds measurably differently to malformed ciphertexts than to correctly PKCS#1 v1.5-padded ciphertexts. The attack requires repeated network observations and RSA-PSK use; the documented impact is indirect confidentiality disclosure without integrity or availability effects.
The record
- CVE
- CVE-2023-5981
- Published
- Nov 28, 2023
- Updated
- Feb 25, 2026
- Vendor
- Red Hat
- Product
- Red Hat Enterprise Linux 8
- Classifications
- CWE-208, CWE-203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Nov 28, 2023CVE publishedPublication date reported by the CVE source.
- Feb 25, 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
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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