CVE-2022-21698

Summary

client_golang is the instrumentation library for Go applications in Prometheus, and the promhttp package in client_golang provides tooling around HTTP servers and clients. In client_golang prior to version 1.11.1, HTTP server is susceptible to a Denial of Service through unbounded cardinality, and potential memory exhaustion, when handling requests with non-standard HTTP methods. In order to be affected, an instrumented software must use any of promhttp.InstrumentHandler* middleware except RequestsInFlight; not filter any specific methods (e.g GET) before middleware; pass metric with method label name to our middleware; and not have any firewall/LB/proxy that filters away requests with unknown method. client_golang version 1.11.1 contains a patch for this issue. Several workarounds are available, including removing the method label name from counter/gauge used in the InstrumentHandler; turning off affected promhttp handlers; adding custom middleware before promhttp handler that will sanitize the request method given by Go http.Request; and using a reverse proxy or web application firewall, configured to only allow a limited set of methods.

Affected Software

VendorProductVersion RangeStatus
prometheusclient_golang< 1.11.1affected

Weaknesses

  • CWE-400: CWE-400: Uncontrolled Resource Consumption

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

References