Ciphertext decryption via RSA timing discrepancy
Published Feb 9, 2024 · Updated Aug 2, 2024
Observable timing discrepancy in wolfSSL 3.12.2 through 5.6.4 allows remote attackers to decrypt ciphertexts via repeated RSA probes. In the SP Math All RSA path, unblinding and big-integer-to-binary conversion leave measurable timing differences instead of running in constant time. Exposure requires a server using TLS 1.2 or earlier with optional static RSA enabled and enough trial connections for statistical analysis; default builds since 3.6.6 are not exposed.
Summary
What happened
Observable timing discrepancy in wolfSSL 3.12.2 through 5.6.4 allows remote attackers to decrypt ciphertexts via repeated RSA probes. In the SP Math All RSA path, unblinding and big-integer-to-binary conversion leave measurable timing differences instead of running in constant time. Exposure requires a server using TLS 1.2 or earlier with optional static RSA enabled and enough trial connections for statistical analysis; default builds since 3.6.6 are not exposed.
The record
- CVE
- CVE-2023-6935
- Published
- Feb 9, 2024
- Updated
- Aug 2, 2024
- Vendor
- wolfSSL
- Product
- wolfSSL
- Classifications
- CWE-203, CAPEC-463, T1040
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 9, 2024CVE publishedPublication date reported by the CVE source.
- Aug 2, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=3.12.2 <=5.6.4
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
- tlsfuzzer Marvin timing-side-channel test suitefunctional · 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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