Vulnerabilities > CVE-2017-12373 - Information Exposure Through Discrepancy vulnerability in Cisco products
Attack vector
NETWORK Attack complexity
MEDIUM Privileges required
NONE Confidentiality impact
PARTIAL Integrity impact
NONE Availability impact
NONE Summary
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.
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| OS | 5 | |
| Hardware | 5 |
Common Weakness Enumeration (CWE)
Metasploit
| description | Some TLS implementations handle errors processing RSA key exchanges and encryption (PKCS #1 v1.5 messages) in a broken way that leads an adaptive chosen-chiphertext attack. Attackers cannot recover a server's private key, but they can decrypt and sign messages with it. A strong oracle occurs when the TLS server does not strictly check message formatting and needs less than a million requests on average to decode a given ciphertext. A weak oracle server strictly checks message formatting and often requires many more requests to perform the attack. This module requires Python 3 with the gmpy2 and cryptography packages to be present. |
| id | MSF:AUXILIARY/SCANNER/SSL/BLEICHENBACHER_ORACLE |
| last seen | 2020-03-09 |
| modified | 2018-08-27 |
| published | 2018-02-02 |
| references |
|
| reporter | Rapid7 |
| source | https://github.com/rapid7/metasploit-framework/blob/master//modules/auxiliary/scanner/ssl/bleichenbacher_oracle.py |
| title | Scanner for Bleichenbacher Oracle in RSA PKCS #1 v1.5 |
Nessus
| NASL family | General |
| NASL id | SSL_ROBOT_BLEICHENBACHER.NASL |
| description | The remote host is affected by an information disclosure vulnerability. The SSL/TLS service supports RSA key exchanges, and incorrectly leaks whether or not the RSA key exchange sent by a client was correctly formatted. This information can allow an attacker to decrypt previous SSL/TLS sessions or impersonate the server. Note that this plugin does not attempt to recover an RSA ciphertext, however it sends a number of correct and malformed RSA ciphertexts as part of an SSL handshake and observes how the server responds. This plugin attempts to discover the vulnerability in multiple ways, by not completing the handshake and by completing it incorrectly, as well as using a variety of cipher suites. Only the first method that finds the service to be vulnerable is reported. This plugin requires report paranoia as some services will report as affected even though the issue is not exploitable. |
| last seen | 2020-04-07 |
| modified | 2017-12-26 |
| plugin id | 105415 |
| published | 2017-12-26 |
| reporter | This script is Copyright (C) 2017-2020 and is owned by Tenable, Inc. or an Affiliate thereof. |
| source | https://www.tenable.com/plugins/nessus/105415 |
| title | Return Of Bleichenbacher's Oracle Threat (ROBOT) Information Disclosure |