Rule Category

SERVER-APACHE -- Snort has detected traffic exploiting vulnerabilities in Apache servers.

Alert Message

SERVER-APACHE Apache mod_session_crypto padding oracle brute force attempt

Rule Explanation

In Apache HTTP Server versions 2.4.0 to 2.4.23, mod_session_crypto was encrypting its data/cookie using the configured ciphers with possibly either CBC or ECB modes of operation (AES256-CBC by default), hence no selectable or builtin authenticated encryption. This made it vulnerable to padding oracle attacks, particularly with CBC. Impact: CVSS base score 7.5 CVSS impact score 3.6 CVSS exploitability score 3.9 confidentialityImpact HIGH 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

Rule Vulnerability

CVE Additional Information

CVE-2016-0736
In Apache HTTP Server versions 2.4.0 to 2.4.23, mod_session_crypto was encrypting its data/cookie using the configured ciphers with possibly either CBC or ECB modes of operation (AES256-CBC by default), hence no selectable or builtin authenticated encryption. This made it vulnerable to padding oracle attacks, particularly with CBC.
Details
Severity Base Score7.5
Impact Score3.6 Exploit Score3.9
Confidentiality ImpactHIGH Integrity ImpactNONE
Availability ImpactNONE Access Vector
Authentication Ease of Access