// For flags

CVE-2019-11727

nss: PKCS#1 v1.5 signatures can be used for TLS 1.3

Severity Score

5.3
*CVSS v3

Exploit Likelihood

< 1%
*EPSS

Affected Versions

1
*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

A vulnerability exists where it possible to force Network Security Services (NSS) to sign CertificateVerify with PKCS#1 v1.5 signatures when those are the only ones advertised by server in CertificateRequest in TLS 1.3. PKCS#1 v1.5 signatures should not be used for TLS 1.3 messages. This vulnerability affects Firefox < 68.

Se presenta una vulnerabilidad donde es posible forzar a Network Security Services (NSS) para firmar CertificateVerify con firmas de PKCS#1 versión v1.5 cuando esas son las únicas anunciadas por el servidor en CertificateRequest en TLS versión 1.3. Las firmas de PKCS#1 versión v1.5 no deben ser usadas para mensajes de TLS versión 1.3. Esta vulnerabilidad afecta a Firefox anterior a versión 68.

A sandbox escape was discovered in Firefox. If a user were tricked in to installing a malicious language pack, an attacker could exploit this to gain additional privileges. Multiple security issues were discovered in Firefox. If a user were tricked in to opening a specially crafted website, an attacker could potentially exploit these to cause a denial of service, obtain sensitive information, bypass same origin restrictions, conduct cross-site scripting attacks, conduct cross-site request forgery attacks, spoof origin attributes, spoof the addressbar contents, bypass safebrowsing protections, or execute arbitrary code. Various other issues were also addressed.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
None
Availability
None
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
None
Integrity
Partial
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2019-05-03 CVE Reserved
  • 2019-07-12 CVE Published
  • 2024-08-04 CVE Updated
  • 2025-03-30 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-295: Improper Certificate Validation
  • CWE-327: Use of a Broken or Risky Cryptographic Algorithm
CAPEC
Affected Vendors, Products, and Versions (1)