How severe is CVE-2020-5243?

CVE-2020-5243 has a CVSS 3.x base score of 5.7, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2020-5243 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-5243?

CVE-2020-5243 affects Uap-core Project Uap-core. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-5243?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2020-5243 published?

CVE-2020-5243 was published on 2020-02-21 and last updated on 2026-06-17.

CVE-2020-5243

CVE-2020-5243 is a medium-severity vulnerability in Uap-core Project Uap-core with a CVSS 3.x base score of 5.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-1333.

Key facts

Severity: Medium (CVSS 3.x base score 5.7)
CVSS v2: 5.0
EPSS exploit prediction: 2% (81st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-1333
Affected product: Uap-core Project Uap-core
Published: 2020-02-21
Last modified: 2026-06-17

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.

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.
How severe is CVE-2020-5243?: CVE-2020-5243 has a CVSS 3.x base score of 5.7, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-5243 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-5243?: CVE-2020-5243 affects Uap-core Project Uap-core. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-5243?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-5243 published?: CVE-2020-5243 was published on 2020-02-21 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:uap-core_project:uap-core:*:*:*:*:*:node.js:*:*

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