Debian Security Advisory

DSA-3688-1 nss -- security update

Date Reported:
05 Oct 2016
Affected Packages:
Security database references:
In the Debian bugtracking system: Bug 583651.
In Mitre's CVE dictionary: CVE-2015-4000, CVE-2015-7181, CVE-2015-7182, CVE-2015-7575, CVE-2016-1938, CVE-2016-1950, CVE-2016-1978, CVE-2016-1979, CVE-2016-2834.
More information:

Several vulnerabilities were discovered in NSS, the cryptography library developed by the Mozilla project.

  • CVE-2015-4000

    David Adrian et al. reported that it may be feasible to attack Diffie-Hellman-based cipher suites in certain circumstances, compromising the confidentiality and integrity of data encrypted with Transport Layer Security (TLS).

  • CVE-2015-7181 CVE-2015-7182 CVE-2016-1950

    Tyson Smith, David Keeler, and Francis Gabriel discovered heap-based buffer overflows in the ASN.1 DER parser, potentially leading to arbitrary code execution.

  • CVE-2015-7575

    Karthikeyan Bhargavan discovered that TLS client implementation accepted MD5-based signatures for TLS 1.2 connections with forward secrecy, weakening the intended security strength of TLS connections.

  • CVE-2016-1938

    Hanno Boeck discovered that NSS miscomputed the result of integer division for certain inputs. This could weaken the cryptographic protections provided by NSS. However, NSS implements RSA-CRT leak hardening, so RSA private keys are not directly disclosed by this issue.

  • CVE-2016-1978

    Eric Rescorla discovered a use-after-free vulnerability in the implementation of ECDH-based TLS handshakes, with unknown consequences.

  • CVE-2016-1979

    Tim Taubert discovered a use-after-free vulnerability in ASN.1 DER processing, with application-specific impact.

  • CVE-2016-2834

    Tyson Smith and Jed Davis discovered unspecified memory-safety bugs in NSS.

In addition, the NSS library did not ignore environment variables in processes which underwent a SUID/SGID/AT_SECURE transition at process start. In certain system configurations, this allowed local users to escalate their privileges.

This update contains further correctness and stability fixes without immediate security impact.

For the stable distribution (jessie), these problems have been fixed in version 2:3.26-1+debu8u1.

For the unstable distribution (sid), these problems have been fixed in version 2:3.23-1.

We recommend that you upgrade your nss packages.