CVE-2013-1620: Medium severity Mozilla Network Security Services 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.
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:
http://www.isg.rhul.ac.uk/tls/TLStiming.pdf
Currently Mozilla is working on final NSS fixes:
https://bugzilla.mozilla.org/showbug.cgi?id=822365
External References:
http://www.isg.rhul.ac.uk/tls/
Other sources
The TLS implementation in Mozilla Network Security Services (NSS) does not properly consider timing side-channel attacks on a noncompliant MAC check operation 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, a related issue to CVE-2013-0169.
Affected Software
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is the severity of CVE-2013-1620?
CVE-2013-1620 has a high severity due to its potential to allow Man-in-the-Middle attacks.
How do I fix CVE-2013-1620?
To fix CVE-2013-1620, update to the appropriate patched versions of the affected packages listed in the advisory.
Which software is affected by CVE-2013-1620?
CVE-2013-1620 affects various versions of Red Hat's NSPR, NSS, and other related software.
What type of attack is associated with CVE-2013-1620?
CVE-2013-1620 is associated with Man-in-the-Middle attacks due to vulnerabilities in CBC-mode encryption.
Is CVE-2013-1620 specific to certain operating systems?
Yes, CVE-2013-1620 specifically impacts software on Red Hat Enterprise Linux and Ubuntu systems among others.