A security issue has been reported in NSS, which can be exploited by a malicious user to disclose certain information.

The issue arises due to an error within the "sslDo1stHandshake()" function in lib/ssl/sslsecur.c, which can be exploited to potentially return unencrypted and unauthenticated data from PRRecv. Successful exploitation requires false start to be enabled.

The issue is said to be fixed in NSS 3.15.4.

References: https://bugs.gentoo.org/showbug.cgi?id=498172 https://developer.mozilla.org/en-US/docs/NSS/NSS3.15.4releasenotes

Upstream bug: https://bugzilla.mozilla.org/showbug.cgi?id=919877

Patch: https://bugzilla.mozilla.org/attachment.cgi?id=825813

Mozilla Network Security Services (NSS) before 3.15.2 does not ensure that data structures are initialized before read operations, which allows remote attackers to cause a denial of service or possibly have unspecified other impact via vectors that trigger a decryption failure.

The ASN.1 decoder in the QuickDER decoder in Mozilla Network Security Services (NSS) before 3.13.4, as used in Firefox 4.x through 12.0, Firefox ESR 10.x before 10.0.5, Thunderbird 5.0 through 12.0, Thunderbird ESR 10.x before 10.0.5, and SeaMonkey before 2.10, allows remote attackers to cause a denial of service (application crash) via a zero-length item, as demonstrated by (1) a zero-length basic constraint or (2) a zero-length field in an OCSP response.