Information disclosure in The Bouncy Castle Crypto Package For Java - CVE-2020-26939
Published: November 2, 2020 / Updated: November 8, 2020
Vulnerability identifier: #VU48199
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2020-26939
CWE-ID: CWE-200
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Legion of the Bouncy Castle Inc.
Affected software:
The Bouncy Castle Crypto Package For Java
The Bouncy Castle Crypto Package For Java
Detailed vulnerability description
The vulnerability allows a remote attacker to gain access to potentially sensitive information.
The vulnerability exists due to observable differences in behavior to error inputs within the org.bouncycastle.crypto.encodings.OAEPEncoding component in Legion of the Bouncy Castle BC. A remote attacker can obtain sensitive information about a private exponent by sending invalid ciphertext that decrypts to a short payload in the OAEP Decoder. This causes the application to throw an early exception, potentially leaking some information about the private exponent of the RSA private key performing the encryption.
How to mitigate CVE-2020-26939
Install updates from vendor's website.