CVE-2020-5243
CVSS v3
7.5
HIGH
EPSS Score
2.3 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
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.
Technical details
- Published
- 2020-02-21
Frequently asked questions
What is CVE-2020-5243?
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.
Is CVE-2020-5243 actively exploited?
Active exploitation of CVE-2020-5243 has not been confirmed. Its EPSS score was 2.3% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2020-5243?
CVE-2020-5243 has a CVSS v3 base score of 7.5 (HIGH severity).
Is CVE-2020-5243 affecting your environment?
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