Message decryption and signature forgery via RSA timing
Published Jan 9, 2025 · Updated Jun 29, 2026
Timing side channel in Ruby OpenSSL allows remote attackers to decrypt messages or forge signatures through crafted RSA ciphertexts. RSA::private_decrypt and PKey::decrypt expose distinguishable execution time and error handling for attacker-controlled PKCS#1 v1.5 ciphertexts instead of implicitly rejecting invalid padding. Reachability requires a service that invokes either method on attacker-controlled messages and permits repeated timing measurements; the consequence is RSA plaintext recovery or signature forgery.
Summary
What happened
Timing side channel in Ruby OpenSSL allows remote attackers to decrypt messages or forge signatures through crafted RSA ciphertexts. RSA::private_decrypt and PKey::decrypt expose distinguishable execution time and error handling for attacker-controlled PKCS#1 v1.5 ciphertexts instead of implicitly rejecting invalid padding. Reachability requires a service that invokes either method on attacker-controlled messages and permits repeated timing measurements; the consequence is RSA plaintext recovery or signature forgery.
The record
- CVE
- CVE-2025-0306
- Published
- Jan 9, 2025
- Updated
- Jun 29, 2026
- Vendor
- libwww-perl
- Product
- Ruby
- Classifications
- CWE-385, T1552.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 9, 2025CVE publishedPublication date reported by the CVE source.
- Jun 29, 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?
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- Affected versionversion=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
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Weakness, pattern, technique
Public exploit references
- Marvin Toolkitfunctional · demonstrated
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Technologies
Your stack
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Your stack
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