Impact
When body-parser is configured with an invalid limit option value, such as an unparseable string or NaN, bytes.parse() returns null and the request body size check is silently skipped. Applications that rely on limit as their primary safeguard against oversized request bodies will accept arbitrarily large payloads, leading to excessive memory and CPU usage and denial of service.
This issue affects applications that pass a programmatically computed or user-configurable value to the limit option without validating it first.
Patches
This issue is fixed in body-parser@2.3.0 and body-parser@1.20.6 via #698. After the fix, invalid limit values throw a clear error at parser construction time instead of silently disabling enforcement. null and undefined continue to fall back to the default limit (100kb).
Workarounds
Validate limit before passing it to body-parser. For example, parse the value with bytes.parse() at startup and reject any configuration where it returns null or a non-finite number.
References
References
Phillip9587 Reporter
efekrskl Remediation reviewer
UlisesGascon Remediation reviewer
bjohansebas Analyst
Impact
When body-parser is configured with an invalid
limitoption value, such as an unparseable string orNaN,bytes.parse()returnsnulland the request body size check is silently skipped. Applications that rely onlimitas their primary safeguard against oversized request bodies will accept arbitrarily large payloads, leading to excessive memory and CPU usage and denial of service.This issue affects applications that pass a programmatically computed or user-configurable value to the
limitoption without validating it first.Patches
This issue is fixed in body-parser@2.3.0 and body-parser@1.20.6 via #698. After the fix, invalid
limitvalues throw a clear error at parser construction time instead of silently disabling enforcement.nullandundefinedcontinue to fall back to the default limit (100kb).Workarounds
Validate
limitbefore passing it to body-parser. For example, parse the value withbytes.parse()at startup and reject any configuration where it returnsnullor a non-finite number.References
References