CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
Percentile
27.9%
Autoinstrumentation out of the box adds the label http_method
that has unbound cardinality. It leads to the server’s potential memory exhaustion when many malicious requests are sent.
HTTP method for requests can be easily set by an attacker to be random and long.
Send many requests with long randomly generated HTTP methods and observe how memory consumption increases during it. The app can be like this example from the official docs.
In order to be affected program has to be instrumented for HTTP handlers and does not filter any unknown HTTP methods on the level of CDN, LB, previous middleware, etc.
For convenience and safe usage of this library, it should by default mark with the label UNKNOWN
non-standard HTTP methods to show that such requests were made (and this way does not increase cardinality). In case someone wants to stay with the current behavior, library API should allow it. The mechanism with environment variables can be reused - introduce the variable OTEL_INSTRUMENTATION_HTTP_CAPTURE_ALL_METHODS
that will allow enabling current behavior when someone really wants it.
github.com/open-telemetry/opentelemetry-python-contrib
github.com/open-telemetry/opentelemetry-python-contrib/commit/6007e0c013071e7f8b9612d3bc68aeb9d600d74e
github.com/open-telemetry/opentelemetry-python-contrib/releases/tag/v0.41b0
github.com/open-telemetry/opentelemetry-python-contrib/security/advisories/GHSA-5rv5-6h4r-h22v
nvd.nist.gov/vuln/detail/CVE-2023-43810