CoreCVE
Back

HIGH

SSL/TLS: Birthday attack against 64-bit block ciphers (SWEET32)

Published Sep 1, 2016

Description

The DES and Triple DES ciphers, as used in the TLS, SSH, and IPSec protocols and other protocols and products, have a birthday bound of approximately four billion blocks, which makes it easier for remote attackers to obtain cleartext data via a birthday attack against a long-duration encrypted session, as demonstrated by an HTTPS session using Triple DES in CBC mode, aka a "Sweet32" attack.

Affected products

Remediation

Red Hat statement

OpenSSL security update RHSA-2016:1940 mitigates this issue by lowering priority of DES cipher suites so they are not preferred over cipher suites using AES. For compatibility reasons, DES cipher suites remain enabled by default and included in the set of cipher suites identified by the HIGH cipher string. Future updates may move them to MEDIUM or not enable them by default. NSS addressed this issue by implementing limits on the amount of plain text which can be encrypted by using the same key. Once the limit is reached, the keys will need to be re-negotiated manually. This change will be available in nss-3.27. GnuTLS is not affected by this issue, since it prioritizes AES before 3DES in the cipher list.

Red Hat mitigation

1.SSL/TLS configurations should prefer AES over DES. Versions of OpenSSL shipped with Red Hat Enterprise Linux 6 and 7 already do so. In the version of OpenSSL shipped with Red Hat Enterprise Linux 5, 3DES is listed below the AES-256 cipher and above the AES-128 cipher, therefore AES-256 based ciphersuite should not be disabled on the server. 2. Servers using OpenSSL, should not disable AES-128 and AES-256 ciphersuites. Versions of Apache shipped with Red Hat Enterprise Linux use the default cipher string, in which AES is preferred over DES/3DES based ciphersuites. For JBoss Middleware, and Java mitigations, please review this knowledge base article: https://access.redhat.com/articles/2598471 This can be mitigated on OpenShift Container Platform (OCP) by disabling the vulnerable TLS cipher suite in the applicable component. TLS configuration options for OCP are described here: https://access.redhat.com/articles/5348961

Metrics

Weaknesses (2)

CWE-200

Exposure of Sensitive Information

CWE-327

Broken Crypto Algorithm

References (141)

Change history (0)

No recorded changes yet.

Sources
CVE.org / MITRE
Status PUBLISHED
Assigner redhat
Published Sep 1, 2016
Updated May 29, 2026
Reserved Jan 29, 2016
Link CVE-2016-2183
CISA Vulnrichment
Updated May 29, 2026
NVD
Status Modified
Modified Jun 17, 2026
Link CVE-2016-2183
Red Hat
Severity Moderate
Public date Aug 24, 2016
Links CVE-2016-2183 - Bugzilla