vulnerability / NVI-00016350 / Revision 1
Netty: Security Control Bypass via CORS Short-Circuit Failure
GitHub lists this reviewed advisory for io.netty:netty-codec-http, io.netty:netty-codec-http. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
6.5 medium
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
io.netty:netty-codec-http
source listed>= 4.2.0.Final, < 4.2.16.Final
### Summary Netty's CorsHandler provides a `shortCircuit()` configuration designed to reject unauthorized cross-origin requests immediately, acting as a security control before requests reach the application. However, due to a logical operator error in the origin evaluation process, this protection can be entirely bypassed. An attacker can bypass the short-circuit mechanism by sending a request with an `Origin: null` header. This failure forwards unauthorized requests to the backend application, bypassing intended access controls. ### Details In `io.netty.handler.codec.http.cors.CorsHandler#channelRead`, the short-circuit logic relies on the configuration returned by `getForOrigin(origin)` to determine if an origin is authorized. If `getForOrigin` returns a configuration object, the short-circuit check `(!(origin == null || config != null))` is bypassed, and the request proceeds to the backend. The vulnerability is located in the `getForOrigin` method: ```java if (corsConfig.isNullOriginAllowed() || NULL_ORIGIN.equals(requestOrigin)) { return corsConfig; } ``` If an attacker sends `Origin: null`, `NULL_ORIGIN.equals(requestOrigin)` evalua
io.netty:netty-codec-http
source listed< 4.1.136.Final
### Summary Netty's CorsHandler provides a `shortCircuit()` configuration designed to reject unauthorized cross-origin requests immediately, acting as a security control before requests reach the application. However, due to a logical operator error in the origin evaluation process, this protection can be entirely bypassed. An attacker can bypass the short-circuit mechanism by sending a request with an `Origin: null` header. This failure forwards unauthorized requests to the backend application, bypassing intended access controls. ### Details In `io.netty.handler.codec.http.cors.CorsHandler#channelRead`, the short-circuit logic relies on the configuration returned by `getForOrigin(origin)` to determine if an origin is authorized. If `getForOrigin` returns a configuration object, the short-circuit check `(!(origin == null || config != null))` is bypassed, and the request proceeds to the backend. The vulnerability is located in the `getForOrigin` method: ```java if (corsConfig.isNullOriginAllowed() || NULL_ORIGIN.equals(requestOrigin)) { return corsConfig; } ``` If an attacker sends `Origin: null`, `NULL_ORIGIN.equals(requestOrigin)` evalua
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-6cqp-g7gg-8hr5 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.