How severe is CVE-2020-13758?

CVE-2020-13758 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2020-13758 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-13758?

CVE-2020-13758 affects Bitrix Bitrix24. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-13758?

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

When was CVE-2020-13758 published?

CVE-2020-13758 was published on 2020-06-01 and last updated on 2026-06-17.

CVE-2020-13758

CVE-2020-13758 is a medium-severity vulnerability in Bitrix Bitrix24 with a CVSS 3.x base score of 6.1. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 1% (54th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Bitrix Bitrix24
Published: 2020-06-01
Last modified: 2026-06-17

Description

modules/security/classes/general.post_filter.php/post_filter.php in the Web Application Firewall in Bitrix24 through 20.0.950 allows XSS by placing %00 before the payload.

Frequently asked questions

What is CVE-2020-13758?: modules/security/classes/general.post_filter.php/post_filter.php in the Web Application Firewall in Bitrix24 through 20.0.950 allows XSS by placing %00 before the payload.
How severe is CVE-2020-13758?: CVE-2020-13758 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2020-13758 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-13758?: CVE-2020-13758 affects Bitrix Bitrix24. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-13758?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-13758 published?: CVE-2020-13758 was published on 2020-06-01 and last updated on 2026-06-17.

References

https://blog.deteact.com/bitrix-waf-bypass/

Affected products (1)

cpe:2.3:a:bitrix:bitrix24:*:*:*:*:*:*:*:*

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