SB2020052811 - Ubuntu update for OpenSSL
Published: May 28, 2020
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 secuirty vulnerabilities.
1) Cryptographic issues (CVE-ID: CVE-2019-1547)
The vulnerability allows a remote attacker to decrypt traffic.
The vulnerability exists due to insufficient enforcement of side channel resistant code paths. A remote attacker with ability to create a large number of signatures, where explicit parameters with no co-factor is present, can force the application to fall back to non-side channel resistant code pathsduring ECDSA signature operation and perform full key recovery.
Successful exploitation of the vulnerability may allow an attacker to decrypt communication between server and client.
2) Protection Mechanism Failure (CVE-ID: CVE-2019-1549)
The vulnerability allows a remote attacker to bypass certain security restrictions.
The vulnerability exists due to OpenSSL does not use by default a rewritten random number generator (RNG) in the event of a fork() system call, resulting in the child and parent processes share the same RNG state.
3) Cryptographic issues (CVE-ID: CVE-2019-1551)
The vulnerability allows a remote attacker to gain access to sensitive information.
The vulnerability exists due to an overflow issue within the rsaz_512_sqr(): the x64_64 Montgomery squaring procedure used in exponentiation with 512-bit moduli. A remote attacker can perform an attack against DH512 keys.
4) Padding oracle attack (CVE-ID: CVE-2019-1563)
The vulnerability allows a remote attacker to perform padding oracle attack.
The vulnerability exists due to possibility to perform a Bleichenbacher padding oracle attack against the RSA key, in situations where an attacker receives automated notification of the success or failure of a decryption attempt an attacker. A remote attacker can send a very large number of messages to be decrypted, can recover a CMS/PKCS7 transported encryption key or decrypt any RSA encrypted message that was encrypted with the public RSA key.
Remediation
Install update from vendor's website.