Authorization headers are cleared on cross-origin redirect. However, cookie headers which are sensitive headers and are official headers found in the spec, remain uncleared. There are active users using cookie headers in undici. This may lead to accidental leakage of cookie to a 3rd-party site or a malicious attacker who can control the redirection target (ie. an open redirector) to leak the cookie to the 3rd party site. This was patched in v5.7.1. By default, this vulnerability is not exploitable. Do not enable redirections, i.e. `maxRedirections: 0` (the default).

Affected: npm: undici

### Impact

Authorization headers are already cleared on cross-origin redirect in https://github.com/nodejs/undici/blob/main/lib/handler/redirect.js#L189, based on https://github.com/nodejs/undici/issues/872.

However, cookie headers which are sensitive headers and are official headers found in the spec, remain uncleared. There also has been active discussion of implementing a cookie store https://github.com/nodejs/undici/pull/1441, which suggests that there are active users using cookie headers in undici. As such this may lead to accidental leakage of cookie to a 3rd-party site or a malicious attacker who can control the redirection target (ie. an open redirector) to leak the cookie to the 3rd party site.

### Patches

This was patched in v5.8.0.

### Workarounds

By default, this vulnerability is not exploitable. Do not enable redirections, i.e. `maxRedirections: 0` (the default).

### References

https://hackerone.com/reports/1635514 https://curl.se/docs/CVE-2018-1000007.html https://curl.se/docs/CVE-2022-27776.html

### For more information If you have any questions or comments about this advisory: * Open an issue in [undici repository](https://github.com/nodejs/undici/issues) * To make a report, follow the [SECURITY](https://github.com/nodejs/node/blob/HEAD/SECURITY.md) document

golang: crypto/tls: session tickets lack random ticket_age_add moment: inefficient parsing algorithm resulting in DoS nodejs16: CRLF injection in node-undici nodejs/undici: Cookie headers uncleared on cross-origin redirect vm2: Sandbox Escape in vm2

Affected: Ubuntu:24.04:LTS: node-undici, Ubuntu:25.10: node-undici, Ubuntu:26.04:LTS: node-undici

Authorization headers are cleared on cross-origin redirect. However, cookie headers which are sensitive headers and are official headers found in the spec, remain uncleared. There are active users using cookie headers in undici. This may lead to accidental leakage of cookie to a 3rd-party site or a malicious attacker who can control the redirection target (ie. an open redirector) to leak the cookie to the 3rd party site. This was patched in v5.7.1. By default, this vulnerability is not exploitable. Do not enable redirections, i.e. `maxRedirections: 0` (the default).