Vulnerability ID | VCID-vz46-gfhm-aaap |
Aliases |
CVE-2016-0800
VC-OPENSSL-20160301-CVE-2016-0800 |
Summary | A cross-protocol attack was discovered that could lead to decryption of TLS sessions by using a server supporting SSLv2 and EXPORT cipher suites as a Bleichenbacher RSA padding oracle. Note that traffic between clients and non-vulnerable servers can be decrypted provided another server supporting SSLv2 and EXPORT ciphers (even with a different protocol such as SMTP, IMAP or POP) shares the RSA keys of the non-vulnerable server. This vulnerability is known as DROWN (CVE-2016-0800). Recovering one session key requires the attacker to perform approximately 2^50 computation, as well as thousands of connections to the affected server. A more efficient variant of the DROWN attack exists against unpatched OpenSSL servers using versions that predate 1.0.2a, 1.0.1m, 1.0.0r and 0.9.8zf released on 19/Mar/2015 (see CVE-2016-0703 below). Users can avoid this issue by disabling the SSLv2 protocol in all their SSL/TLS servers, if they've not done so already. Disabling all SSLv2 ciphers is also sufficient, provided the patches for CVE-2015-3197 (fixed in OpenSSL 1.0.1r and 1.0.2f) have been deployed. Servers that have not disabled the SSLv2 protocol, and are not patched for CVE-2015-3197 are vulnerable to DROWN even if all SSLv2 ciphers are nominally disabled, because malicious clients can force the use of SSLv2 with EXPORT ciphers. OpenSSL 1.0.2g and 1.0.1s deploy the following mitigation against DROWN: SSLv2 is now by default disabled at build-time. Builds that are not configured with "enable-ssl2" will not support SSLv2. Even if "enable-ssl2" is used, users who want to negotiate SSLv2 via the version-flexible SSLv23_method() will need to explicitly call either of: SSL_CTX_clear_options(ctx, SSL_OP_NO_SSLv2); or SSL_clear_options(ssl, SSL_OP_NO_SSLv2); as appropriate. Even if either of those is used, or the application explicitly uses the version-specific SSLv2_method() or its client or server variants, SSLv2 ciphers vulnerable to exhaustive search key recovery have been removed. Specifically, the SSLv2 40-bit EXPORT ciphers, and SSLv2 56-bit DES are no longer available. In addition, weak ciphers in SSLv3 and up are now disabled in default builds of OpenSSL. Builds that are not configured with "enable-weak-ssl-ciphers" will not provide any "EXPORT" or "LOW" strength ciphers. |
Status | Published |
Exploitability | 2.0 |
Weighted Severity | 9.0 |
Risk | 10.0 |
Affected and Fixed Packages | Package Details |
Data source | Metasploit |
---|---|
Description | Check if a server supports a given version of SSL/TLS and cipher suites. The certificate is stored in loot, and any known vulnerabilities against that SSL version and cipher suite combination are checked. These checks include POODLE, deprecated protocols, expired/not valid certs, low key strength, null cipher suites, certificates signed with MD5, DROWN, RC4 ciphers, exportable ciphers, LOGJAM, and BEAST. |
Note | {} |
Ransomware campaign use | Unknown |
Source publication date | Oct. 14, 2014 |
Source URL | https://github.com/rapid7/metasploit-framework/tree/master/modules/auxiliary/scanner/ssl/ssl_version.rb |
Exploitability (E) | Access Vector (AV) | Access Complexity (AC) | Authentication (Au) | Confidentiality Impact (C) | Integrity Impact (I) | Availability Impact (A) |
---|---|---|---|---|---|---|
high functional unproven proof_of_concept not_defined |
local adjacent_network network |
high medium low |
multiple single none |
none partial complete |
none partial complete |
none partial complete |
Attack Vector (AV) | Attack Complexity (AC) | Privileges Required (PR) | User Interaction (UI) | Scope (S) | Confidentiality Impact (C) | Integrity Impact (I) | Availability Impact (A) |
---|---|---|---|---|---|---|---|
network adjacent_network local physical |
low high |
none low high |
none required |
unchanged changed |
high low none |
high low none |
high low none |
Attack Vector (AV) | Attack Complexity (AC) | Privileges Required (PR) | User Interaction (UI) | Scope (S) | Confidentiality Impact (C) | Integrity Impact (I) | Availability Impact (A) |
---|---|---|---|---|---|---|---|
network adjacent_network local physical |
low high |
none low high |
none required |
unchanged changed |
high low none |
high low none |
high low none |
Attack Vector (AV) | Attack Complexity (AC) | Privileges Required (PR) | User Interaction (UI) | Scope (S) | Confidentiality Impact (C) | Integrity Impact (I) | Availability Impact (A) |
---|---|---|---|---|---|---|---|
network adjacent_network local physical |
low high |
none low high |
none required |
unchanged changed |
high low none |
high low none |
high low none |
Attack Vector (AV) | Attack Complexity (AC) | Privileges Required (PR) | User Interaction (UI) | Scope (S) | Confidentiality Impact (C) | Integrity Impact (I) | Availability Impact (A) |
---|---|---|---|---|---|---|---|
network adjacent_network local physical |
low high |
none low high |
none required |
unchanged changed |
high low none |
high low none |
high low none |
Attack Vector (AV) | Attack Complexity (AC) | Privileges Required (PR) | User Interaction (UI) | Scope (S) | Confidentiality Impact (C) | Integrity Impact (I) | Availability Impact (A) |
---|---|---|---|---|---|---|---|
network adjacent_network local physical |
low high |
none low high |
none required |
unchanged changed |
high low none |
high low none |
high low none |
Attack Vector (AV) | Attack Complexity (AC) | Privileges Required (PR) | User Interaction (UI) | Scope (S) | Confidentiality Impact (C) | Integrity Impact (I) | Availability Impact (A) |
---|---|---|---|---|---|---|---|
network adjacent_network local physical |
low high |
none low high |
none required |
unchanged changed |
high low none |
high low none |
high low none |
Percentile | 0.9946 |
EPSS Score | 0.88377 |
Published At | May 2, 2025, 12:55 p.m. |
Date | Actor | Action | Source | VulnerableCode Version |
---|---|---|---|---|
There are no relevant records. |