Vulnerability · Published Feb 20, 2020 · Assigned by GitHub_M
CVE-2020-5243Denial of Service in uap-core when processing crafted User-Agent strings
Medium 5.7
In plain English
A medium-severity improper input validation in uap-core from ua-parser. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 2.3% (higher than 83% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
uap-core before 0.7.3 is vulnerable to a denial of service attack when processing crafted User-Agent strings. 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 has been patched in uap-core 0.7.3.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | uap-core | 1:0.8.0-1 | DEBIAN-CVE-2020-5243 |
| Debian:13 | uap-core | 1:0.8.0-1 | DEBIAN-CVE-2020-5243 |
| Debian:14 | uap-core | 1:0.8.0-1 | DEBIAN-CVE-2020-5243 |
| RubyGems | user_agent_parser | 2.6.0 | GHSA-cmcx-xhr8-3w9p |
| Ubuntu:22.04:LTS | uap-core | no fix listed | UBUNTU-CVE-2020-5243 |
| Ubuntu:24.04:LTS | uap-core | no fix listed | UBUNTU-CVE-2020-5243 |
| Ubuntu:25.10 | uap-core | no fix listed | UBUNTU-CVE-2020-5243 |
| Ubuntu:26.04:LTS | uap-core | no fix listed | UBUNTU-CVE-2020-5243 |
| Ubuntu:26.10 | uap-core | no fix listed | UBUNTU-CVE-2020-5243 |
| npm | uap-core | 0.7.3 | GHSA-cmcx-xhr8-3w9p |
Affected products (as reported)
Weakness: CWE-20 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H