CVE-2013-0169: Low severity OpenSSL OpenSSL vulnerability
A flaw in how TLS/DTLS, when CBC-mode encryption is used, communicates was reported. This vulnerability can allow for a Man-in-the-Middle attacker to recover plaintext from a TLS/DTLS connection, when CBC-mode encryption is used.
This flaw is in the TLS specification, and not a bug in a specific implementation (as such, it affects nearly all implementations). As such, it affects all TLS and DTLS implementations that are compliant with TLS 1.1 or 1.2, or with DTLS 1.0 or 1.2. It also applies to implementations of SSL 3.0 and TLS 1.0 that incorporate countermeasures to deal with previous padding oracle attacks. All TLS/DTLS ciphersuites that include CBC-mode encryption are potentially vulnerable.
The paper indicates that with OpenSSL, a full plaintext recovery attack is possible, and with GnuTLS, a partial plaintext recovery is possible (recovering up to 4 bits of the last byte in any block of plaintext).
To perform a successful attack, when TLS is used, a large number of TLS sessions are required (target plaintext must be sent repeatedly in the same position in the plaintext stream across the sessions). For DTLS, a successful attack can be carried out in a single session. The attacker must also be located close to the machine being attacked.
Further details are noted in the paper.
Current status of fixes in various implementations:
OpenSSL has a patch in development NSS has a patch in development GnuTLS is fixed in versions 2.12.23, 3.0.28, and 3.1.7 PolarSSL is fixed in version 1.2.5 BouncyCastle has a patch that will be included in the forthcoming 1.48 version
Full paper:
http://www.isg.rhul.ac.uk/tls/TLStiming.pdf
External References:
http://www.isg.rhul.ac.uk/tls/ http://www.openssl.org/news/secadv20130205.txt https://polarssl.org/tech-updates/releases/polarssl-1.2.5-released
Other sources
The TLS protocol 1.1 and 1.2 and the DTLS protocol 1.0 and 1.2, as used in OpenSSL, OpenJDK, PolarSSL, and other products, do not properly consider timing side-channel attacks on a MAC check requirement during the processing of malformed CBC padding, which allows remote attackers to conduct distinguishing attacks and plaintext-recovery attacks via statistical analysis of timing data for crafted packets, aka the "Lucky Thirteen" issue.
Affected Software
Remediation
Information
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is the severity of CVE-2013-0169?
CVE-2013-0169 is a critical vulnerability that allows a Man-in-the-Middle attacker to recover plaintext data from a TLS/DTLS connection.
How do I fix CVE-2013-0169?
To fix CVE-2013-0169, update to the recommended versions of affected software such as OpenJDK or OpenSSL as specified in the remediation guidelines.
Which software is affected by CVE-2013-0169?
CVE-2013-0169 affects various versions of OpenJDK and OpenSSL configured with CBC-mode encryption.
What types of attacks can exploit CVE-2013-0169?
CVE-2013-0169 can be exploited in Man-in-the-Middle attacks targeting insecure TLS/DTLS connections.
How was CVE-2013-0169 discovered?
CVE-2013-0169 was identified as a flaw in the TLS specification related to CBC-mode encryption.