Debian DLA-507-1 : nss security update (Logjam)
Medium Nessus Plugin ID 91505
SynopsisThe remote Debian host is missing a security update.
DescriptionA vulnerability has been found in nss.
With TLS protocol 1.2 and earlier, when a DHE_EXPORT ciphersuite is enabled on a server but not on a client, does not properly convey a DHE_EXPORT choice, which allows man-in-the-middle attackers to conduct cipher-downgrade attacks by rewriting a ClientHello with DHE replaced by DHE_EXPORT and then rewriting a ServerHello with DHE_EXPORT replaced by DHE, aka the 'Logjam' issue.
The solution in nss was to not accept bit lengths less than 1024. This may potentially be a backwards incompatibility issue but such low bit lengths should not be in use so it was deemed acceptable.
For Debian 7 'Wheezy', these problems have been fixed in version 2:3.14.5-1+deb7u7.
We recommend that you upgrade your nss packages.
NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
SolutionUpgrade the affected packages.