Authentication token theft via unvalidated realm redirect
Published Jul 22, 2025 · Updated Oct 17, 2025
Cross-domain token exposure in Ollama 0.9.6 and earlier allows remote attackers to steal registry bearer tokens during model pulls. server.auth.getAuthorizationToken follows the realm URL from an HTTP 401 WWW-Authenticate response without verifying that its host matches the requested registry, then sends a bearer token through the redirected flow. Exploitation requires a user to pull from an attacker-controlled HTTPS server; the captured token grants access to private models and, when authorized, model publishing.
Summary
What happened
Cross-domain token exposure in Ollama 0.9.6 and earlier allows remote attackers to steal registry bearer tokens during model pulls. server.auth.getAuthorizationToken follows the realm URL from an HTTP 401 WWW-Authenticate response without verifying that its host matches the requested registry, then sends a bearer token through the redirected flow. Exploitation requires a user to pull from an attacker-controlled HTTPS server; the captured token grants access to private models and, when authorized, model publishing.
The record
- CVE
- CVE-2025-51471
- Published
- Jul 22, 2025
- Updated
- Oct 17, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-384, CWE-345, T1528
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 22, 2025CVE publishedPublication date reported by the CVE source.
- Oct 17, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Cross-domain token-capture proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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