Resource exhaustion in Ua-Parser Uap-Core
CVE-2021-21317
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.
Vulnerability class: DoS (Denial of Service)
EPSS: 0.025 (83.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
Affected products
- Ua-parser Uap-core — versions < 0.11.0
- Uap-core_project Uap-core
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Product, Third Party Advisory, x_refsource_MISC)
Frequently asked questions
- What is CVE-2021-21317?
- CVE-2021-21317 is a medium-severity vulnerability in Ua-Parser Uap-Core, classified under Uncontrolled Resource Consumption. CVSS score: 5.3/10. Published 2021-02-16.
- How severe is CVE-2021-21317?
- Medium severity. CVSS v3 base score is 5.3 out of 10.
- Is CVE-2021-21317 known to be exploited?
- 5 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.