CVE-2023-3817:Issue summary: Checking excessively long DH keys or parameters may be very slow. Impact summary: Applications that use the functions DH_check(), DH_check_ex() or EVP_PKEY_param_check() to check a DH key or DH parameters may experience long delays. Where the key or parameters that are being checked have been obtained from an untrusted source this may lead to a Denial of Service. The function DH_check() performs various checks on DH parameters. After fixing CVE-2023-3446 it was discovered that a large q parameter value can also trigger an overly long computation during some of these checks. A correct q value, if present, cannot be larger than the modulus p parameter, thus it is unnecessary to perform these checks if q is larger than p. An application that calls DH_check() and supplies a key or parameters obtained from an untrusted source could be vulnerable to a Denial of Service attack. The function DH_check() is itself called by a number of other OpenSSL functions. An application calling any of those other functions may similarly be affected. The other functions affected by this are DH_check_ex() and EVP_PKEY_param_check(). Also vulnerable are the OpenSSL dhparam and pkeyparam command line applications when using the "-check" option. The OpenSSL SSL/TLS implementation is not affected by this issue. The OpenSSL 3.0 and 3.1 FIPS providers are not affected by this issue.

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Issue summary: Checking excessively long DH keys or parameters may be very slow.

Impact summary: Applications that use the functions DH_check(), DH_check_ex() or EVP_PKEY_param_check() to check a DH key or DH parameters may experience long delays. Where the key or parameters that are being checked have been obtained from an untrusted source this may lead to a Denial of Service.

The function DH_check() performs various checks on DH parameters. After fixing CVE-2023-3446 it was discovered that a large q parameter value can also trigger an overly long computation during some of these checks. A correct q value, if present, cannot be larger than the modulus p parameter, thus it is unnecessary to perform these checks if q is larger than p.

An application that calls DH_check() and supplies a key or parameters obtained from an untrusted source could be vulnerable to a Denial of Service attack.

The function DH_check() is itself called by a number of other OpenSSL functions. An application calling any of those other functions may similarly be affected. The other functions affected by this are DH_check_ex() and EVP_PKEY_param_check().

Also vulnerable are the OpenSSL dhparam and pkeyparam command line applications when using the "-check" option.

The OpenSSL SSL/TLS implementation is not affected by this issue.

The OpenSSL 3.0 and 3.1 FIPS providers are not affected by this issue.

Industry ExposureMost to least
This section illustrates the prevalence of a specific Common Vulnerabilities and Exposures (CVE) across various industries based on customer reports. The ranking displays industries from the most to least affected by this particular vulnerability, offering valuable insight into where this CVE has been most frequently observed. This information can help organizations within these sectors prioritize their security efforts, understand their relative risk exposure compared to their peers, and focus remediation strategies where they are most needed. By understanding the industry-specific impact, organizations can make more informed decisions regarding patching, resource allocation, and overall risk management related to this CVE.

  1. Health Care & Social Assistance
    Health Care & Social Assistance
  2. Manufacturing
    Manufacturing
  3. Public Administration
    Public Administration
  4. Educational Services
    Educational Services
  5. Finance and Insurance
    Finance and Insurance
  6. Professional, Scientific, & Technical Services
    Professional, Scientific, & Technical Services
  7. Transportation & Warehousing
    Transportation & Warehousing
  8. Utilities
    Utilities
  9. Retail Trade
    Retail Trade
  10. Other Services (except Public Administration)
    Other Services (except Public Administration)
  11. Information
    Information
  12. Arts, Entertainment & Recreation
    Arts, Entertainment & Recreation
  13. Management of Companies & Enterprises
    Management of Companies & Enterprises
  14. Accommodation & Food Services
    Accommodation & Food Services
  15. Mining
    Mining
  16. Agriculture, Forestry Fishing & Hunting
    Agriculture, Forestry Fishing & Hunting
  17. Construction
    Construction
  18. Real Estate Rental & Leasing
    Real Estate Rental & Leasing
  19. Administrative, Support, Waste Management & Remediation Services
    Administrative, Support, Waste Management & Remediation Services
  20. Wholesale Trade
    Wholesale Trade

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