CVE intelligence and bounded remediation

CVE-2020-11993 — Apache Http Server security vulnerability

High CVSS 7.5

Apache HTTP Server versions 2.4.20 to 2.4.43 When trace/debug was enabled for the HTTP/2 module and on certain traffic edge patterns, logging statements were made on the wrong connection, causing concurrent use of memory pools. Configuring the LogLevel of mod_http2 above "info" will mitigate this vulnerability for unpatched servers.

Severity
High
CVSS
7.5 (3.1)
Published
2020-08-07
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-444

Affected products

  • apache / http_server
  • netapp / clustered_data_ontap
  • canonical / ubuntu_linux / 16.04
  • canonical / ubuntu_linux / 18.04
  • canonical / ubuntu_linux / 20.04
  • opensuse / leap / 15.1

Showing 6 representative product identities from 19 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

HTTP request smuggling and message-boundary ambiguity

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Check exposure

  • Inventory every proxy, CDN, gateway, load balancer, service mesh, and application server hop on affected request paths.
  • Compare documented parsing and normalization behavior for message length, transfer coding, duplicate headers, and protocol translation.
  • Identify connection reuse and which downstream services trust headers added by intermediaries.

Remediate safely

  • Update affected intermediaries and origin servers and align them on a single standards-compliant request framing policy.
  • Reject ambiguous length, transfer-coding, duplicate, malformed, and unsupported framing before forwarding.
  • Normalize or remove hop-by-hop and identity headers at one controlled boundary and add multi-hop regression tests.

Authoritative sources

Complete CVE record and remediation plan

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