Improper Certificate ValidationWeakness · CWE-295

CVE-2024-41996

HIGH · 7.5 CVSS v3.1 Published 2024-08-26
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Validating the order of the public keys in the Diffie-Hellman Key Agreement Protocol, when an approved safe prime is used, allows remote attackers (from the client side) to trigger unnecessarily expensive server-side DHE modular-exponentiation calculations. The client may cause asymmetric resource consumption. The basic attack scenario is that the client must claim that it can only communicate with DHE, and the server must be configured to allow DHE and validate the order of the public key.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

This is a denial-of-service vulnerability in Diffie-Hellman (DHE) key exchange where malicious clients can manipulate public key parameters to force servers into performing computationally expensive modular exponentiation operations. The attack exploits the order validation of DH public keys when using approved safe primes, causing asymmetric resource consumption where minimal client effort triggers significant server-side CPU load.

MitigationDisable DHE cipher suites and use ECDHE (Elliptic Curve Diffie-Hellman) instead, or ensure proper DH parameter validation is implemented to reject invalid public key orders. Alternatively, limit the maximum DH key size accepted.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify if DHE cipher suites are enabled
    Review server SSL/TLS configuration files (e.g., openssl.cnf, nginx.conf, httpd.conf) or run a TLS scan (e.g., nmap --script ssl-enum-ciphers) to list enabled cipher suites and look for DHE variants such as DHE-RSA-AES256-SHA, DHE-RSA-AES128-GCM-SHA256, or similar DHE- prefixed ciphers
    Affected if DHE cipher suites are listed as enabled in the server configuration
  2. Inspect DH parameter validation settings
    Check if the TLS/SSL library or server implementation includes explicit DH public key order validation before proceeding with key exchange. This may be found in library documentation, source code if applicable, or server logs showing validation behavior
    Affected if No explicit order validation is performed on incoming DH public keys, or the implementation relies solely on standard DH library defaults without additional checks
  3. Check for DH key size limits
    Review server configuration for any max DH key size setting (e.g., ssl_dhparam in Apache, ssl_prefer_server_ciphers directives, or custom DH parameter limits). Look for configuration options that restrict maximum acceptable DH key sizes
    Affected if No maximum DH key size limit is configured, allowing arbitrarily large public key parameters to be processed
  4. Identify TLS library version in use
    Determine the version of the TLS library or server software handling Diffie-Hellman key exchanges (e.g., OpenSSL version via 'openssl version', server software version, or library documentation). Compare against any vendor advisories or release notes addressing this vulnerability
    Affected if The TLS library or server software version is older than patches addressing this DoS vulnerability and no compensating controls are in place

A server is affected if it has DHE cipher suites enabled and accepts DH key exchanges without robust order validation or key size limits, allowing a client to trigger disproportionate server-side computational load.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Disable DHE cipher suites and use ECDHE (Elliptic Curve Diffie-Hellman) instead, or ensure proper DH parameter validation is implemented to reject invalid public key orders. Alternatively, limit the maximum DH key size accepted.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-41996 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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