CVE intelligence and bounded remediation

CVE-2021-34585 — In the CODESYS V2 web server prior to V1.1.9.22 crafted web server requests can trigger a parser error

High CVSS 7.5

In the CODESYS V2 web server prior to V1.1.9.22 crafted web server requests can trigger a parser error. Since the parser result is not checked under all conditions, a pointer dereference with an invalid address can occur. This leads to a denial of service situation.

Severity
High
CVSS
7.5 (3.1)
Published
2021-10-26
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-252

Affected products

  • wago / 750-823_firmware
  • wago / 750-829_firmware
  • wago / 750-831_firmware
  • wago / 750-832_firmware
  • wago / 750-852_firmware
  • wago / 750-862_firmware

Showing 6 representative product identities from 28 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Resource exhaustion and denial of service

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify attacker-influenced work factors including input size, nesting, compression, fan-out, regex cost, allocation, recursion, retries, and connection lifetime.
  • Map per-request and shared CPU, memory, disk, descriptor, thread, queue, and downstream-service limits.
  • Determine whether authentication, tenancy, quotas, and rate controls apply before expensive processing begins.

Remediate safely

  • Bound input size, nesting, expansion, work, concurrency, queue depth, retries, and execution time before resource-intensive processing.
  • Release resources on every success, error, cancellation, and timeout path and use backpressure instead of unbounded buffering.
  • Update affected components and add small deterministic tests that assert resource ceilings rather than exhausting a host.

Authoritative sources

Complete CVE record and remediation plan

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