Sid 1-45201

Rule Documentation
References

Rule Category

SERVER-OTHER -- Snort has detected traffic exploiting vulnerabilities in a server in the network.

Alert Message

SERVER-OTHER limited RSA ciphersuite list - possible Bleichenbacher SSL attack attempt

Rule Explanation

This event is generated when a limited number of RSA ciphersuites are used in a SSL client hello, indicating a possible Bleichenbacher padding oracle attack. Impact: Attempted Information Leak Details: Ease of Attack:

What To Look For

Known Usage

No public information

False Positives

No known false positives

Contributors

Cisco Talos Intelligence Group

MITRE ATT&CK Framework

Tactic:

Technique:

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

CVE

CVE-2012-5081 CVE-2016-6883 CVE-2017-1000385 CVE-2017-12373 CVE-2017-13098 CVE-2017-13099 CVE-2017-17382 CVE-2017-17427 CVE-2017-17428 CVE-2017-6168

Additional Links

robotattack.org

tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20171212-bleichenbacher

Rule Vulnerability

CVE Additional Information

CVE-2012-5081

Unspecified vulnerability in the Java Runtime Environment (JRE) component in Oracle Java SE 7 Update 7 and earlier, 6 Update 35 and earlier, 5.0 Update 36 and earlier, and 1.4.2_38 and earlier allows remote attackers to affect availability, related to JSSE.

Details
Severity	MEDIUM	Base Score	5.0
Impact Score	2.9	Exploit Score	10.0
Confidentiality Impact	NONE	Integrity Impact	NONE
Availability Impact	PARTIAL	Access Vector
Authentication	NONE	Ease of Access

CVE-2016-6883

MatrixSSL before 3.8.3 configured with RSA Cipher Suites allows remote attackers to obtain sensitive information via a Bleichenbacher variant attack.

Details
Severity		Base Score	5.9
Impact Score	3.6	Exploit Score	2.2
Confidentiality Impact	HIGH	Integrity Impact	NONE
Availability Impact	NONE	Access Vector
Authentication		Ease of Access

CVE-2017-1000385

The Erlang otp TLS server answers with different TLS alerts to different error types in the RSA PKCS #1 1.5 padding. This allows an attacker to decrypt content or sign messages with the server's private key (this is a variation of the Bleichenbacher attack).

Details
Severity		Base Score	5.9
Impact Score	3.6	Exploit Score	2.2
Confidentiality Impact	HIGH	Integrity Impact	NONE
Availability Impact	NONE	Access Vector
Authentication		Ease of Access

CVE-2017-12373

A vulnerability in the TLS protocol implementation of legacy Cisco ASA 5500 Series (ASA 5505, 5510, 5520, 5540, and 5550) devices could allow an unauthenticated, remote attacker to access sensitive information, aka a Return of Bleichenbacher's Oracle Threat (ROBOT) attack. An attacker could iteratively query a server running a vulnerable TLS stack implementation to perform cryptanalytic operations that may allow decryption of previously captured TLS sessions. Cisco Bug IDs: CSCvg97652.

Details
Severity		Base Score	5.9
Impact Score	3.6	Exploit Score	2.2
Confidentiality Impact	HIGH	Integrity Impact	NONE
Availability Impact	NONE	Access Vector
Authentication		Ease of Access

CVE-2017-13098

BouncyCastle TLS prior to version 1.0.3, when configured to use the JCE (Java Cryptography Extension) for cryptographic functions, provides a weak Bleichenbacher oracle when any TLS cipher suite using RSA key exchange is negotiated. An attacker can recover the private key from a vulnerable application. This vulnerability is referred to as "ROBOT."

Details
Severity		Base Score	5.9
Impact Score	3.6	Exploit Score	2.2
Confidentiality Impact	HIGH	Integrity Impact	NONE
Availability Impact	NONE	Access Vector
Authentication		Ease of Access

CVE-2017-13099

wolfSSL prior to version 3.12.2 provides a weak Bleichenbacher oracle when any TLS cipher suite using RSA key exchange is negotiated. An attacker can recover the private key from a vulnerable wolfSSL application. This vulnerability is referred to as "ROBOT."

Details
Severity		Base Score	5.9
Impact Score	3.6	Exploit Score	2.2
Confidentiality Impact	HIGH	Integrity Impact	NONE
Availability Impact	NONE	Access Vector
Authentication		Ease of Access

CVE-2017-17382

Citrix NetScaler Application Delivery Controller (ADC) and NetScaler Gateway 10.5 before build 67.13, 11.0 before build 71.22, 11.1 before build 56.19, and 12.0 before build 53.22 might allow remote attackers to decrypt TLS ciphertext data by leveraging a Bleichenbacher RSA padding oracle, aka a ROBOT attack.

Details
Severity		Base Score	5.9
Impact Score	3.6	Exploit Score	2.2
Confidentiality Impact	HIGH	Integrity Impact	NONE
Availability Impact	NONE	Access Vector
Authentication		Ease of Access

CVE-2017-17427

Radware Alteon devices with a firmware version between 31.0.0.0-31.0.3.0 are vulnerable to an adaptive-chosen ciphertext attack ("Bleichenbacher attack"). This allows an attacker to decrypt observed traffic that has been encrypted with the RSA cipher and to perform other private key operations.

Details
Severity		Base Score	5.9
Impact Score	3.6	Exploit Score	2.2
Confidentiality Impact	HIGH	Integrity Impact	NONE
Availability Impact	NONE	Access Vector
Authentication		Ease of Access

CVE-2017-17428

Cavium Nitrox SSL, Nitrox V SSL, and TurboSSL software development kits (SDKs) allow remote attackers to decrypt TLS ciphertext data by leveraging a Bleichenbacher RSA padding oracle, aka a ROBOT attack.

Details
Severity		Base Score	5.9
Impact Score	3.6	Exploit Score	2.2
Confidentiality Impact	HIGH	Integrity Impact	NONE
Availability Impact	NONE	Access Vector
Authentication		Ease of Access

CVE-2017-6168

On BIG-IP versions 11.6.0-11.6.2 (fixed in 11.6.2 HF1), 12.0.0-12.1.2 HF1 (fixed in 12.1.2 HF2), or 13.0.0-13.0.0 HF2 (fixed in 13.0.0 HF3) a virtual server configured with a Client SSL profile may be vulnerable to an Adaptive Chosen Ciphertext attack (AKA Bleichenbacher attack) against RSA, which when exploited, may result in plaintext recovery of encrypted messages and/or a Man-in-the-middle (MiTM) attack, despite the attacker not having gained access to the server's private key itself, aka a ROBOT attack.

Details
Severity		Base Score	7.4
Impact Score	5.2	Exploit Score	2.2
Confidentiality Impact	HIGH	Integrity Impact	HIGH
Availability Impact	NONE	Access Vector
Authentication		Ease of Access