SB2020071818 - Debian update for nss



SB2020071818 - Debian update for nss

Published: July 18, 2020

Security Bulletin ID SB2020071818
Severity
High
Patch available
YES
Number of vulnerabilities 4
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 25% Medium 25% Low 50%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 4 secuirty vulnerabilities.


1) Heap-based buffer overflow (CVE-ID: CVE-2019-17006)

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error in Mozilla NSS library when processing input text length while using certain cryptographic primitives. A remote attacker can pass specially crafted data to the application, trigger heap-based buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.


2) Algorithm Downgrade (CVE-ID: CVE-2019-17023)

The vulnerability allows a remote attacker to bypass certain security restrictions.

The vulnerability exists due to insecure negotiation After a HelloRetryRequest in Mozilla NSS that can lead to selection of a less secure protocol (e.g. TLS 1.2 or below) after the HelloRetryRequest TLS 1.3 is sent.


3) Race condition (CVE-ID: CVE-2020-12399)

The vulnerability allows a local user to gain access to sensitive information.

The vulnerability exists due to time differences in Mozilla NSS library during the process of generating a DSA signature, the nonce value 'k' is not padded, exposing the bit length. Combined with other techniques, this can result in the recovery of the DSA private key.


4) Cryptographic issues (CVE-ID: CVE-2020-12402)

The vulnerability allows a remote attacker to recover the secret primes.

During RSA key generation, bignum implementations used a variation of the Binary Extended Euclidean Algorithm which entailed significantly input-dependent flow. This allowed an attacker able to perform electromagnetic-based side channel attacks to record traces leading to the recovery of the secret primes.


Remediation

Install update from vendor's website.