Rule Category

POLICY-OTHER --

Alert Message

POLICY-OTHER SSL/TLS weak RC4 cipher suite use attempt

Rule Explanation

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. Impact: CVSS base score 4.3 CVSS impact score 2.9 CVSS exploitability score 8.6 confidentialityImpact PARTIAL integrityImpact NONE availabilityImpact NONE Details: Ease of Attack:

What To Look For

Known Usage

No public information

False Positives

No known false positives

Contributors

Talos research team. This document was generated from data supplied by the national vulnerability database, a product of the national institute of standards and technology. For more information see [nvd].

MITRE ATT&CK Framework

Tactic:

Technique:

For reference, see the MITRE ATT&CK vulnerability types here: https://attack.mitre.org

CVE

Additional Links

CVE Additional Information

CVE-2015-2808
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.
Details
SeverityMEDIUM Base Score4.3
Impact Score2.9 Exploit Score8.6
Confidentiality ImpactPARTIAL Integrity ImpactNONE
Availability ImpactNONE Access Vector
AuthenticationNONE Ease of Access