Amazon Linux AMI Security Advisory: ALAS-2020-1421
Advisory Release Date: 2020-08-26 23:09 Pacific
Advisory Updated Date: 2020-08-31 20:16 Pacific
Python-RSA before 4.1 ignores leading '\0' bytes during decryption of ciphertext. This could conceivably have a security-relevant impact, e.g., by helping an attacker to infer that an application uses Python-RSA, or if the length of accepted ciphertext affects application behavior (such as by causing excessive memory allocation). A flaw was found in the python-rsa package, where it does not explicitly check the ciphertext length against the key size and ignores the leading 0 bytes during the decryption of the ciphertext. This flaw allows an attacker to perform a ciphertext attack, leading to a denial of service. The highest threat from this vulnerability is to confidentiality. (CVE-2020-13757 )
Run yum update python-rsa to update your system.