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GHSA-qgc4-8p88-4w7m
No affected components available
Impact
The Express server uses express.json() without a size limit, which can allow attackers to send extremely large request bodies. This may lead to excessive memory usage, degraded performance, or process crashes, resulting in a Denial of Service (DoS). Any application using the JSON parser without limits and exposed to untrusted clients is affected.
Patches
This issue is not a flaw in Express itself but in configuration. Users should set a request-size limit when enabling the JSON body parser. For example:
app.use(express.json({ limit: "100kb" }));
Workarounds
Users can mitigate the issue without upgrading by:
- Adding a
limitoption to the JSON parser - Implementing rate limiting at the application or reverse-proxy level
- Rejecting unusually large requests before parsing
- Using a reverse proxy (such as NGINX) to enforce maximum request body sizes
The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability.
Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.
The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.
We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.
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