// For flags

CVE-2020-12403

nss: CHACHA20-POLY1305 decryption with undersized tag leads to out-of-bounds read

Severity Score

9.1
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

A flaw was found in the way CHACHA20-POLY1305 was implemented in NSS in versions before 3.55. When using multi-part Chacha20, it could cause out-of-bounds reads. This issue was fixed by explicitly disabling multi-part ChaCha20 (which was not functioning correctly) and strictly enforcing tag length. The highest threat from this vulnerability is to confidentiality and system availability.

Se encontró un fallo en la manera en que se implementó CHACHA20-POLY1305 en NSS en versiones anteriores a 3.55. Cuando es usado Chacha20 de múltiples partes, podría causar lecturas fuera de límites. Este problema fue corregido al desactivar explícitamente ChaCha20 de múltiples partes (que no funcionaba correctamente) y aplicando estrictamente la longitud de la etiqueta. La mayor amenaza de esta vulnerabilidad es la confidencialidad y la disponibilidad del sistema

A flaw was found in the way CHACHA20-POLY1305 was implemented in NSS. When using multi-part Chacha20, it could cause out-of-bounds reads. This issue was fixed by explicitly disabling multi-part ChaCha20 (which was not functioning correctly) and strictly enforcing tag length. The highest threat from this vulnerability is to confidentiality and system availability.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
None
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2020-04-28 CVE Reserved
  • 2020-08-19 CVE Published
  • 2024-02-10 EPSS Updated
  • 2024-08-04 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-125: Out-of-bounds Read
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Mozilla
Search vendor "Mozilla"
Nss
Search vendor "Mozilla" for product "Nss"
< 3.55
Search vendor "Mozilla" for product "Nss" and version " < 3.55"
-
Affected