REDHAT-BUG-2227852: Low severity OpenSSL OpenSSL vulnerability

Published Jul 31, 2023
·
Updated

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256

OpenSSL Security Advisory [31st July 2023] ==========================================

Excessive time spent checking DH q parameter value (CVE-2023-3817) ==================================================================

Severity: Low

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

Impact summary: Applications that use the functions DHcheck(), DHcheckex() or EVPPKEYparamcheck() 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 DHcheck() 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 DHcheck() and supplies a key or parameters obtained from an untrusted source could be vulnerable to a Denial of Service attack.

The function DHcheck() 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 DHcheckex() and EVPPKEYparamcheck().

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.

OpenSSL 3.1, 3.0, 1.1.1 and 1.0.2 are vulnerable to this issue.

Due to the low severity of this issue we are not issuing new releases of OpenSSL at this time. The fix will be included in the next releases when they become available. The fix is also available in commit 6a1eb62c2 (for 3.1), commit 9002fd073 (for 3.0) and commit 91ddeba0f (for 1.1.1) in the OpenSSL git repository. It is available to premium support customer in commit 869ad69a (for 1.0.2).

This issue was reported on 20th July 2023 by Bernd Edlinger. The fix was developed by Tomas Mraz.

General Advisory Notes ======================

URL for this Security Advisory: https://www.openssl.org/news/secadv/20230731.txt

Note: the online version of the advisory may be updated with additional details over time.

For details of OpenSSL severity classifications please see: https://www.openssl.org/policies/secpolicy.html

OpenSSL 1.1.1 will reach end-of-life on 2023-09-11. After that date security fixes for 1.1.1 will only be available to premium support customers. -----BEGIN PGP SIGNATURE-----

iQEzBAEBCAAdFiEEhlersmDwVrHlGQg52cTSbQ5gRJEFAmTH1M4ACgkQ2cTSbQ5g RJGhtAf9E3HklBKezKOXvAbsPmCqcjySMVTV/JrBjrDn14UIRjZmhVoHd5QGusN2 ReRtA3bRL41UQYdLKDkdYjp9XmlDDFb5hKO3G7P0ldtDaw21TkIQeI/90OKjgsQu A+vpf/TcE1a1Pbz8cIRKYBjIaS3z9yIDW4eB0gytWxsqMxze+9IOYNuAbDa0KsqO PFTUiHr5xu01wsdVdHeUMpZ01E8tGbVwgyY7tvCUAUJcjjLcTb9+gXQLn6cmVRJt 6kU8jsamkiYpL1MoKI5yQvYx0nXZUxXbH1ICPltytC4pBsMEypCCnJTkcJKhRRNt 76Z4/x3XDqMzapYMPimIRifdzPV9FQ== =Ve/V -----END PGP SIGNATURE-----

Affected Software

1 affected component
OpenSSL OpenSSL=3.1, =3.0, =1.1.1, =1.0.2

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade OpenSSL to a version that resolves this vulnerability.

    Patch CVE-2023-3446
  2. Upgrade

    Upgrade OpenSSL to a version that resolves this vulnerability.

    Patch CVE-2023-3817
  3. Upgrade

    Upgrade OpenSSL to a version that resolves this vulnerability.

    Patch commit 6a1eb62c2 (for 3.1)
  4. Upgrade

    Upgrade OpenSSL to a version that resolves this vulnerability.

    Patch commit 9002fd073 (for 3.0)
  5. Upgrade

    Upgrade OpenSSL to a version that resolves this vulnerability.

    Patch commit 91ddeba0f (for 1.1.1)
  6. Compensating control

    Avoid invoking OpenSSL DH key/parameter validation functions on attacker-controlled or untrusted DH values (e.g., do not call DH_check(), DH_check_ex(), EVP_PKEY_param_check() or related DH parameter checks with keys/parameters obtained from an untrusted source), since excessive computation can lead to a Denial of Service.

Event History

Jul 31, 2023
Data Sourced
via Red Hat·05:51 PM
DescriptionSeverityAffected Software
Free Weekly Intel

Don't miss critical vulnerabilities

Join thousands of security professionals who receive our weekly digest of trending CVEs, zero-days, and exploited vulnerabilities.

No spam. Unsubscribe anytime.

Frequently Asked Questions

1

What is the severity of REDHAT-BUG-2227852?

The severity of REDHAT-BUG-2227852 is classified as high due to potential excessive resource consumption resulting from DH parameter validation.

2

How do I fix REDHAT-BUG-2227852?

To fix REDHAT-BUG-2227852, upgrade to OpenSSL version 1.1.1 or later to ensure proper handling of DH parameters.

3

What systems are affected by REDHAT-BUG-2227852?

REDHAT-BUG-2227852 affects OpenSSL versions between 1.0.2 and 1.1.1.

4

What exploit does REDHAT-BUG-2227852 address?

REDHAT-BUG-2227852 addresses an exploit that allows for excessive resource consumption during DH parameter validation, potentially leading to denial of service.

5

Is there a workaround for REDHAT-BUG-2227852?

A temporary workaround for REDHAT-BUG-2227852 may involve implementing strict validation rules for DH parameters until the software is updated.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203