Rule Category

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

Alert Message

SERVER-OTHER SSL export grade ciphersuite server negotiation attempt

Rule Explanation

The ssl3_get_key_exchange function in s3_clnt.c in OpenSSL before 0.9.8zd, 1.0.0 before 1.0.0p, and 1.0.1 before 1.0.1k allows remote SSL servers to conduct RSA-to-EXPORT_RSA downgrade attacks and facilitate brute-force decryption by offering a weak ephemeral RSA key in a noncompliant role, related to the "FREAK" issue. NOTE: the scope of this CVE is only client code based on OpenSSL, not EXPORT_RSA issues associated with servers or other TLS implementations. Impact: CVSS base score 4.3 CVSS impact score 2.9 CVSS exploitability score 8.6 confidentialityImpact NONE integrityImpact PARTIAL availabilityImpact PARTIAL Details: Ease of Attack:

What To Look For

No information provided

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].

Rule Groups

No rule groups

CVE

Additional Links

Rule Vulnerability

CVE Additional Information

CVE-2015-0204
The ssl3_get_key_exchange function in s3_clnt.c in OpenSSL before 0.9.8zd, 1.0.0 before 1.0.0p, and 1.0.1 before 1.0.1k allows remote SSL servers to conduct RSA-to-EXPORT_RSA downgrade attacks and facilitate brute-force decryption by offering a weak ephemeral RSA key in a noncompliant role, related to the "FREAK" issue. NOTE: the scope of this CVE is only client code based on OpenSSL, not EXPORT_RSA issues associated with servers or other TLS implementations.
Details
SeverityMEDIUM Base Score4.3
Impact Score2.9 Exploit Score8.6
Confidentiality ImpactNONE Integrity ImpactPARTIAL
Availability ImpactNONE Access Vector
AuthenticationNONE Ease of Access
CVE-2015-1637
Schannel (aka Secure Channel) in Microsoft Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, and Windows RT Gold and 8.1 does not properly restrict TLS state transitions, which makes it easier for remote attackers to conduct cipher-downgrade attacks to EXPORT_RSA ciphers via crafted TLS traffic, related to the "FREAK" issue, a different vulnerability than CVE-2015-0204 and CVE-2015-1067.
Details
SeverityMEDIUM Base Score4.3
Impact Score2.9 Exploit Score8.6
Confidentiality ImpactNONE Integrity ImpactPARTIAL
Availability ImpactNONE Access Vector
AuthenticationNONE Ease of Access
CVE-2015-4000
The TLS protocol 1.2 and earlier, when a DHE_EXPORT ciphersuite is enabled on a server but not on a client, does not properly convey a DHE_EXPORT choice, which allows man-in-the-middle attackers to conduct cipher-downgrade attacks by rewriting a ClientHello with DHE replaced by DHE_EXPORT and then rewriting a ServerHello with DHE_EXPORT replaced by DHE, aka the "Logjam" issue.
Details
Severity Base Score3.7
Impact Score1.4 Exploit Score2.2
Confidentiality ImpactNONE Integrity ImpactLOW
Availability ImpactNONE Access Vector
Authentication Ease of Access