From $URL :
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
dev-libs/nss-3.14.2 is in the tree now. Dunno if that contains a fix for this problem though.
(In reply to comment #1)
> dev-libs/nss-3.14.2 is in the tree now. Dunno if that contains a fix for
> this problem though.
No it does not contain the fix, I am adding 3.14.3 to tree in next couple of minutes which does tho :)
Feel free to bring in the archs, nss-3.14.3 is now in the tree.
(In reply to comment #3)
> Feel free to bring in the archs, nss-3.14.3 is now in the tree.
Arches, please test and mark stable
The following keyword changes are necessary to proceed:
(see "package.accept_keywords" in the portage(5) man page for more details)
#required by dev-libs/nss-3.14.3, required by =dev-libs/nss-3.14.3 (argument)
Any objection in getting that one stable as well?
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.
Added to existing GLSA request.
This issue was resolved and addressed in
GLSA 201406-19 at http://security.gentoo.org/glsa/glsa-201406-19.xml
by GLSA coordinator Mikle Kolyada (Zlogene).