How severe is CVE-2024-21496?

CVE-2024-21496 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-2024-21496 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-21496?

CVE-2024-21496 affects Authcrunch Caddy-security. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2024-21496?

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

Does CVE-2024-21496 have an EU (EUVD) identifier?

Yes. CVE-2024-21496 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-0628.

When was CVE-2024-21496 published?

CVE-2024-21496 was published on 2024-02-17 and last updated on 2026-06-17.

CVE-2024-21496

CVE-2024-21496 is a medium-severity vulnerability in Authcrunch Caddy-security 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)
EPSS exploit prediction: 1% (43rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-0628
Weakness: CWE-79
Affected product: Authcrunch Caddy-security
Published: 2024-02-17
Last modified: 2026-06-17

Description

All versions of the package github.com/greenpau/caddy-security are vulnerable to Cross-site Scripting (XSS) via the Referer header, due to improper input sanitization. Although the Referer header is sanitized by escaping some characters that can allow XSS (e.g., [&], [<], [>], ["], [']), it does not account for the attack based on the JavaScript URL scheme (e.g., javascript:alert(document.domain)// payload). Exploiting this vulnerability may not be trivial, but it could lead to the execution of malicious scripts in the context of the target user’s browser, compromising user sessions.

Frequently asked questions

What is CVE-2024-21496?: All versions of the package github.com/greenpau/caddy-security are vulnerable to Cross-site Scripting (XSS) via the Referer header, due to improper input sanitization. Although the Referer header is sanitized by escaping some characters that can allow XSS (e.g., [&], [<], [>], ["], [']), it does not account for the attack based on the JavaScript URL scheme (e.g., javascript:alert(document.domain)// payload). Exploiting this vulnerability may not be trivial, but it could lead to the execution of malicious scripts in the context of the target user’s browser, compromising user sessions.
How severe is CVE-2024-21496?: CVE-2024-21496 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-2024-21496 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-21496?: CVE-2024-21496 affects Authcrunch Caddy-security. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2024-21496?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2024-21496 have an EU (EUVD) identifier?: Yes. CVE-2024-21496 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-0628.
When was CVE-2024-21496 published?: CVE-2024-21496 was published on 2024-02-17 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:authcrunch:caddy-security:-:*:*:*:*:*:*:*

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