CVE Vulnerabilities

CVE-2020-12399

Observable Discrepancy

Published: Jul 09, 2020 | Modified: Jan 04, 2022
CVSS 3.x
4.4
MEDIUM
Source:
NVD
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:N/A:N
CVSS 2.x
1.2 LOW
AV:L/AC:H/Au:N/C:P/I:N/A:N
RedHat/V2
RedHat/V3
4.4 MODERATE
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:N/A:N
Ubuntu
MEDIUM

NSS has shown timing differences when performing DSA signatures, which was exploitable and could eventually leak private keys. This vulnerability affects Thunderbird < 68.9.0, Firefox < 77, and Firefox ESR < 68.9.

Weakness

The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor, which exposes security-relevant information about the state of the product, such as whether a particular operation was successful or not.

Affected Software

Name Vendor Start Version End Version
Firefox Mozilla * 77.0 (excluding)
Firefox_esr Mozilla * 68.9.0 (excluding)
Thunderbird Mozilla * 68.9.0 (excluding)
Red Hat Enterprise Linux 8 RedHat nspr-0:4.25.0-2.el8_2 *
Red Hat Enterprise Linux 8 RedHat nss-0:3.53.1-11.el8_2 *
Firefox Ubuntu bionic *
Firefox Ubuntu devel *
Firefox Ubuntu eoan *
Firefox Ubuntu focal *
Firefox Ubuntu trusty *
Firefox Ubuntu upstream *
Firefox Ubuntu xenial *
Nss Ubuntu bionic *
Nss Ubuntu devel *
Nss Ubuntu eoan *
Nss Ubuntu focal *
Nss Ubuntu trusty *
Nss Ubuntu trusty/esm *
Nss Ubuntu upstream *
Nss Ubuntu xenial *
Thunderbird Ubuntu bionic *
Thunderbird Ubuntu devel *
Thunderbird Ubuntu eoan *
Thunderbird Ubuntu focal *
Thunderbird Ubuntu trusty *
Thunderbird Ubuntu upstream *
Thunderbird Ubuntu xenial *

Potential Mitigations

  • Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
  • Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
  • Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success.
  • If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files.
  • Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not.

References