Summary
Blnk has an API key authorization bypass in owner and scope enforcement
Blnk API key endpoints had an authorization issue that allowed non-master API keys to perform key-management actions outside their intended authorization boundary.
In affected versions, API key operations trusted caller-controlled request values for owner and scope decisions. As a result, a non-master API key could potentially manage keys for another owner by supplying a different owner value, or create a more privileged API key by requesting broader scopes than it already had.
This has been fixed by deriving the effective owner from the authenticated API key and enforcing scope coverage checks when creating new keys.
Details
The API key authorization flow previously trusted request data supplied by the caller when deciding which owner a key-management operation applied to and which scopes could be granted.
This meant a non-master API key could potentially:
- create API keys for another owner
- list API keys belonging to another owner
- revoke API keys belonging to another owner
- create a new API key with broader scopes than the caller’s own scopes
The patched version changes this behavior for non-master API keys:
- the effective owner is derived from the authenticated API key
- caller-supplied owner values are no longer trusted for authorization decisions
- cross-owner key operations are rejected with
403 Forbidden - requested scopes must be covered by the caller’s existing scopes
- master-key behavior is unchanged
Affected versions
Versions up to and including v0.14.2 are affected.
Patched versions
This issue is fixed in v0.14.3.
Users should upgrade to v0.14.3 or later.
Workarounds
If developers cannot upgrade their applications immediately, restrict access to API key management endpoints to trusted master keys only.
Where possible, disable or block non-master API key access to key creation, listing, and revocation endpoints until the patched version is deployed.
Credits
Blank thanks @Shivam8584 for identifying and fixing this issue.
Impact
A non-master API key with access to API key management endpoints could potentially perform unauthorized key-management operations across owners or escalate its permissions by creating a new API key with broader scopes.
Deployments using API keys for programmatic key creation, listing, or revocation should upgrade.
The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions. Typical impact: unauthorized data access or execution of privileged operations.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
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Frequently Asked Questions
- What is GHSA-WCR3-9X4C-F5GJ? GHSA-WCR3-9X4C-F5GJ is a high-severity incorrect authorization vulnerability in github.com/blnkfinance/blnk (go), affecting versions <= 0.14.2. It is fixed in 0.14.3. The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions.
- Which versions of github.com/blnkfinance/blnk are affected by GHSA-WCR3-9X4C-F5GJ? github.com/blnkfinance/blnk (go) versions <= 0.14.2 is affected.
- Is there a fix for GHSA-WCR3-9X4C-F5GJ? Yes. GHSA-WCR3-9X4C-F5GJ is fixed in 0.14.3. Upgrade to this version or later.
- Is GHSA-WCR3-9X4C-F5GJ exploitable, and should I be worried? Whether GHSA-WCR3-9X4C-F5GJ is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-WCR3-9X4C-F5GJ is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-WCR3-9X4C-F5GJ? Upgrade
github.com/blnkfinance/blnkto 0.14.3 or later.