CVE-2023-27492 Envoy may crash when a large request body is processed in Lua filter
Attackers can crash Envoy proxy by sending large request bodies to routes with the Lua filter enabled, requiring an upgrade to fix.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2023-27492?
CVE-2023-27492 is a medium-severity denial of service vulnerability in Envoyproxy Envoy, published on 4 Apr 2023. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, the Lua filter is vulnerable to denial of service. Attackers can send large request bodies for routes that have Lua filter enabled and trigger crashes.
As of versions versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, Envoy no longer invokes the Lua coroutine if the filter has been reset. As a workaround for those whose Lua filter is buffering all requests/ responses, mitigate by using the buffer filter to avoid triggering the local reply in the Lua filter.
Weakness: CWE-770
Which versions are affected by CVE-2023-27492?
1 open source package ship an affected version, including envoy. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
envoy Bitnami | All versions | 1.22.9, 1.23.6, 1.24.4, 1.25.3 |
Products include Envoyproxy Envoy.
How do I fix CVE-2023-27492?
Upgrade envoy to a fixed version for your release line: 1.22.9, 1.23.6, 1.24.4 or 1.25.3.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2023-27492 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-27492 exists.
Other vulnerabilities in Envoyproxy Envoy
Sources
Also known as BIT-envoy-2023-27492, GHSA-wpc2-2jp6-ppg2.