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H3-2020-0026

Vulnerable SSL RC4 Algorithm

Category SECURITY_MISCONFIGURATION
Base Score 0.1

Description

The RC4 algorithm, as used in the TLS protocol and SSL protocol, does not properly combine state data with key data during the initialization phase, which makes it easier for remote attackers to conduct plaintext-recovery attacks against the initial bytes of a stream by sniffing network traffic that occasionally relies on keys affected by the Invariance Weakness, and then using a brute-force approach involving LSB values, aka the "Bar Mitzvah" issue.

The RC4 algorithm, as used in the TLS protocol and SSL protocol, has many single-byte biases, which makes it easier for remote attackers to conduct plaintext-recovery attacks via statistical analysis of ciphertext in a large number of sessions that use the same plaintext.

Impact

Attackers can derive what key was used to encrypt SSL traffic. This will allow further decryption of other cipher texts encrypted with the same key.

References