CVE-2025-27143
Beter Auth has an Open Redirect via Scheme-Less Callback Parameter
Published Feb 24, 2025
CVSS 4.0 · 6.9 Medium
EPSS < 1%
KEV · Not listed
Description
Better Auth is an authentication and authorization library for TypeScript. Prior to version 1.1.21, the application is vulnerable to an open redirect due to improper validation of the callbackURL parameter in the email verification endpoint and any other endpoint that accepts callback url. While the server blocks fully qualified URLs, it incorrectly allows scheme-less URLs. This results in the browser interpreting the URL as a fully qualified URL, leading to unintended redirection. An attacker can exploit this flaw by crafting a malicious verification link and tricking users into clicking it. Upon successful email verification, the user will be automatically redirected to the attacker's website, which can be used for phishing, malware distribution, or stealing sensitive authentication tokens. This CVE is a bypass of the fix for GHSA-8jhw-6pjj-8723/CVE-2024-56734. Version 1.1.21 contains an updated patch.
Analysis
Affected Products
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CVE record
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NVD configurations
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Red Hat packages
No data
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OpenCVE enrichment
No data
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| better-auth | better-auth | affected |
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No data.
No data available yet.
Remediation
Tracking
Advisories
| Source | ID | Title |
|---|---|---|
 EUVD |
EUVD-2025-4279 | Better Auth is an authentication and authorization library for TypeScript. Prior to version 1.1.21, the application is vulnerable to an open redirect due to improper validation of the callbackURL parameter in the email verification endpoint and any other endpoint that accepts callback url. While the server blocks fully qualified URLs, it incorrectly allows scheme-less URLs. This results in the browser interpreting the URL as a fully qualified URL, leading to unintended redirection. An attacker can exploit this flaw by crafting a malicious verification link and tricking users into clicking it. Upon successful email verification, the user will be automatically redirected to the attacker's website, which can be used for phishing, malware distribution, or stealing sensitive authentication tokens. This CVE is a bypass of the fix for GHSA-8jhw-6pjj-8723/CVE-2024-56734. Version 1.1.21 contains an updated patch. |
 Github GHSA |
GHSA-hjpm-7mrm-26w8 | Beter Auth has an Open Redirect via Scheme-Less Callback Parameter |
Metrics
Attack Vector Network
Attack Complexity Low
Privileges Required None
Attack Requirements None
User Interaction None
Vulnerable System Confidentiality Impact None
Vulnerable System Integrity Impact None
Vulnerable System Availability Impact None
Subsequent System Confidentiality Impact Low
Subsequent System Integrity Impact Low
Subsequent System Availability Impact None
Attack Vector Network
Attack Complexity Low
Privileges Required None
Scope Changed
Confidentiality Impact Low
Integrity Impact Low
Availability Impact None
User Interaction Required
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.350% probability within 30 days)
Exploitation poc
Automatable yes
Technical Impact partial
References
History
Feb 28, 2025 4:30 PM
First appearance in the feed. Affected versions updated. Affected vendors updated. Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Better-auth
Better-auth better Auth |
|
| CPEs | cpe:2.3:a:better-auth:better_auth:*:*:*:*:*:node.js:*:* | |
| Vendors & Products |
Better-auth
Better-auth better Auth |
|
| Metrics |
cvssV3_1
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Feb 25, 2025 3:15 PM
Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Feb 24, 2025 10:30 PM
Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Better Auth is an authentication and authorization library for TypeScript. Prior to version 1.1.21, the application is vulnerable to an open redirect due to improper validation of the callbackURL parameter in the email verification endpoint and any other endpoint that accepts callback url. While the server blocks fully qualified URLs, it incorrectly allows scheme-less URLs. This results in the browser interpreting the URL as a fully qualified URL, leading to unintended redirection. An attacker can exploit this flaw by crafting a malicious verification link and tricking users into clicking it. Upon successful email verification, the user will be automatically redirected to the attacker's website, which can be used for phishing, malware distribution, or stealing sensitive authentication tokens. This CVE is a bypass of the fix for GHSA-8jhw-6pjj-8723/CVE-2024-56734. Version 1.1.21 contains an updated patch. | |
| Title | Beter Auth has an Open Redirect via Scheme-Less Callback Parameter | |
| Weaknesses | CWE-601 | |
| References |
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| Metrics |
cvssV4_0
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Subscriptions
Weaknesses
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CWE-601
URL Redirection to Untrusted Site ('Open Redirect')
