Headline
GHSA-q2qj-628g-vhfw: Insecure header validation in slim/psr7
Impact
An attacker could sneak in a newline (\n) into both the header names and values. While the specification states that \r\n\r\n is used to terminate the header list, many servers in the wild will also accept \n\n. An attacker that is able to control the header names that are passed to Slilm-Psr7 would be able to intentionally craft invalid messages, possibly causing application errors or invalid HTTP requests being sent out with an PSR-18 HTTP client. The latter might present a denial of service vector if a remote service’s web application firewall bans the application due to the receipt of malformed requests.
Patches
The issue is patched in 1.6.1
Workarounds
In Slim-Psr7 1.6.0 and below, validate HTTP header keys and/or values, and if using user-supplied values, filter them to strip off leading or trailing newline characters before calling withHeader().
Acknowledgments
We are very grateful to and thank <a href="https://gjcampbell.co.uk/">Graham Campbell</a> for reporting and working with us on this issue.
References
- Guzzle: CVE-2023-29197, with advisory GHSA-wxmh-65f7-jcvw
- Laminas Diactoros: CVE-2023-29530, with advisory GHSA-xv3h-4844-9h36
- https://www.rfc-editor.org/rfc/rfc7230#section-3.2.4
- GitHub Advisory Database
- GitHub Reviewed
- CVE-2023-30536
Insecure header validation in slim/psr7
Moderate severity GitHub Reviewed Published Apr 17, 2023 in slimphp/Slim-Psr7 • Updated Apr 18, 2023
Package
Affected versions
< 1.6.1
Impact
An attacker could sneak in a newline (\n) into both the header names and values. While the specification states that \r\n\r\n is used to terminate the header list, many servers in the wild will also accept \n\n. An attacker that is able to control the header names that are passed to Slilm-Psr7 would be able to intentionally craft invalid messages, possibly causing application errors or invalid HTTP requests being sent out with an PSR-18 HTTP client. The latter might present a denial of service vector if a remote service’s web application firewall bans the application due to the receipt of malformed requests.
Patches
The issue is patched in 1.6.1
Workarounds
In Slim-Psr7 1.6.0 and below, validate HTTP header keys and/or values, and if using user-supplied values, filter them to strip off leading or trailing newline characters before calling withHeader().
Acknowledgments
We are very grateful to and thank Graham Campbell for reporting and working with us on this issue.
References
- Guzzle: CVE-2023-29197, with advisory GHSA-wxmh-65f7-jcvw
- Laminas Diactoros: CVE-2023-29530, with advisory GHSA-xv3h-4844-9h36
- https://www.rfc-editor.org/rfc/rfc7230#section-3.2.4
References
- GHSA-q2qj-628g-vhfw
- https://nvd.nist.gov/vuln/detail/CVE-2023-30536
- slimphp/Slim-Psr7@ed1d553
- https://www.rfc-editor.org/rfc/rfc7230#section-3.2.4
Published to the GitHub Advisory Database
Apr 18, 2023
Last updated
Apr 18, 2023
Related news
slim/psr7 is a PSR-7 implementation for use with Slim 4. In versions prior to 1.6.1 an attacker could sneak in a newline (\n) into both the header names and values. While the specification states that \r\n\r\n is used to terminate the header list, many servers in the wild will also accept \n\n. An attacker that is able to control the header names that are passed to Slilm-Psr7 would be able to intentionally craft invalid messages, possibly causing application errors or invalid HTTP requests being sent out with an PSR-18 HTTP client. The latter might present a denial of service vector if a remote service’s web application firewall bans the application due to the receipt of malformed requests. The issue has been patched in version 1.6.1. There are no known workarounds to this issue. Users are advised to upgrade.