Package Instance

Mozilla has updated the version of Network Security Services
(NSS) library used in Firefox to NSS 3.23. This addresses four moderate rated
networking security issues reported by Mozilla engineers Tyson Smith and
Jed Davis.

Multiple vulnerabilities have been found in Mozilla Firefox and
    Thunderbird, the worst of which may allow user-assisted execution of
    arbitrary code.

The NSS code used for checking PKCS#1 v1.5 was leaking information useful in mounting Bleichenbacher-like attacks.
Both the overall correctness of the padding as well as the length of the encrypted message was leaking through timing side-channel.
By sending large number of attacker-selected ciphertexts, the attacker would be able to decrypt a previously intercepted PKCS#1 v1.5 ciphertext (for example, to decrypt a TLS session that used RSA key exchange), or forge a signature using the victim's key.
The issue was fixed by implementing the implicit rejection algorithm, in which the NSS returns a deterministic random message in case invalid padding is detected, as proposed in the Marvin Attack paper.

Multiple vulnerabilities have been found in Firefox, Thunderbird,
    Network Security Services (NSS), and NetScape Portable Runtime (NSPR) with
    the worst of which may allow remote execution of arbitrary code.