VulnerabilityPublished 17 Feb 2024Updated 3 Mar 2026

CVE-2024-21497: github.com/greenpau/caddy-security · Open Redirect

Affects github.com/greenpau/caddy-securitySource CVE Database V5

Not known to be exploited · CVSS 5.4 Medium.

Data as of 26 Oct 2026, 08:30 UTC

CVSS 3.1 base score

5.4Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 42% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N/E:P

Base metrics

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: None

Temporal metrics

Exploit Code Maturity: Proof-of-Concept

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.
Exploit Code Maturity: Proof-of-Concept: Proof-of-concept exploit code is available, or an attack demonstration is not practical for most systems. The code or technique is not functional in all situations and may require substantial modification by a skilled attacker.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 17 Feb 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Gogithub.com/greenpau/caddy-security`pkg:golang/github.com/greenpau/caddy-security`Other threats	Affected =0	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

To mitigate CVE-2024-21497, organizations should immediately update the github.com/greenpau/caddy-security package to a version where the vulnerability is patched once available. In the interim, developers should implement strict validation and sanitization of the redirect_url parameter to ensure it only allows redirection to trusted internal URLs or domains. Employing a whitelist approach for redirect destinations is recommended. Additionally, consider implementing user warnings or confirmation prompts before redirection occurs to untrusted sites. Security teams should audit web applications for usage of this package and review all redirect mechanisms for similar vulnerabilities. Monitoring user reports and logs for suspicious redirect activity can help detect exploitation attempts. Educating users about the risks of clicking unexpected links and promoting cautious behavior can reduce the success of phishing attempts leveraging this vulnerability. Finally, integrating Content Security Policy (CSP) headers and other browser security features can help mitigate the impact of malicious redirects.

Description

Versions of the package github.com/greenpau/caddy-security are vulnerable to Open Redirect via the redirect_url parameter. An attacker could perform a phishing attack and trick users into visiting a malicious website by crafting a convincing URL with this parameter. To exploit this vulnerability, the user must take an action, such as clicking on a portal button or using the browser’s back button, to trigger the redirection.

Impact

The primary impact of this vulnerability is the facilitation of phishing attacks through open redirect abuse. Attackers can exploit this flaw to redirect users from a trusted domain to malicious websites, potentially leading to credential theft, malware downloads, or other social engineering attacks. While the vulnerability does not directly compromise system confidentiality, integrity, or availability, it undermines user trust and can serve as a vector for broader attacks. Organizations using the vulnerable package in their web applications risk exposing their users to phishing scams, which can result in reputational damage, loss of customer trust, and potential regulatory consequences if user data is compromised. The requirement for user interaction limits automated exploitation but does not eliminate risk, especially in environments with high user traffic or where users are less security-aware. Since the vulnerability affects a security-related package, its presence could weaken the overall security posture of affected applications.

References

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