Secret disclosure via compiler-induced carry branch
Published Oct 23, 2024 · Updated Oct 24, 2024
Observable discrepancy in Botan before 3.6.0 allows remote attackers to infer cryptographic secrets through operation timing. In 32-bit donna128 builds, GCC can compile a carry comparison into a secret-dependent branch that skips the high-word addition when no carry is set. Exposure requires affected 32-bit code compiled with a triggering GCC optimization and use of ChaCha-Poly1305 or X25519 operations observable to the attacker.
Summary
What happened
Observable discrepancy in Botan before 3.6.0 allows remote attackers to infer cryptographic secrets through operation timing. In 32-bit donna128 builds, GCC can compile a carry comparison into a secret-dependent branch that skips the high-word addition when no carry is set. Exposure requires affected 32-bit code compiled with a triggering GCC optimization and use of ChaCha-Poly1305 or X25519 operations observable to the attacker.
The record
- CVE
- CVE-2024-50383
- Published
- Oct 23, 2024
- Updated
- Oct 24, 2024
- Vendor
- Botan Project
- Product
- Botan
- Classifications
- CWE-203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 23, 2024CVE publishedPublication date reported by the CVE source.
- Oct 24, 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=0 <3.6.0
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
- Breaking Bad evaluation infrastructureproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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