RSA plaintext disclosure via non-constant-time decryption
Published Mar 6, 2024 · Updated Feb 25, 2026
A timing side channel in Libgcrypt before 9.4.0 allows remote attackers to decrypt RSA ciphertexts through repeated trial requests. RSA decryption uses non-constant-time MPI blinding removal and integer-to-byte conversion that strips leading zeroes, exposing plaintext-dependent timing. Successful exploitation requires observing enough decipher operations, and the impact is limited to confidentiality of RSA-protected data.
Summary
What happened
A timing side channel in Libgcrypt before 9.4.0 allows remote attackers to decrypt RSA ciphertexts through repeated trial requests. RSA decryption uses non-constant-time MPI blinding removal and integer-to-byte conversion that strips leading zeroes, exposing plaintext-dependent timing. Successful exploitation requires observing enough decipher operations, and the impact is limited to confidentiality of RSA-protected data.
The record
- CVE
- CVE-2024-2236
- Published
- Mar 6, 2024
- Updated
- Feb 25, 2026
- Vendor
- Red Hat
- Product
- Red Hat Enterprise Linux 8
- Classifications
- CWE-385
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 6, 2024CVE 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
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
- Marvin Toolkit Libgcrypt test harnessproof 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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