CVEvulnerability

CVE-2021-21317

5.3 MEDIUM Published 2021-02-16 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2021-02-16
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
5.3 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS 3.1 ([email protected])
5.3 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS 2.0 ([email protected])
5.0 MEDIUM — AV:N/AC:L/Au:N/C:N/I:N/A:P
Weaknesses
CWE-1333, CWE-400

Description

uap-core in an open-source npm package which contains the core of BrowserScope's original user agent string parser. In uap-core before version 0.11.0, some regexes are vulnerable to regular expression denial of service (REDoS) due to overlapping capture groups. This allows remote attackers to overload a server by setting the User-Agent header in an HTTP(S) request to maliciously crafted long strings. This is fixed in version 0.11.0. Downstream packages such as uap-python, uap-ruby etc which depend upon uap-core follow different version schemes.

Affected configurations

• uap-core project uap-core (< 0.11.0)

Related

Weakness · CWE (2)

  • CWE-1333 Inefficient Regular Expression Complexity weakness
  • CWE-400 Uncontrolled Resource Consumption weakness

Referenced by CWE · observed example (1)

  • CWE-1333 Inefficient Regular Expression Complexity weakness

References