Inefficient Regular Expression Complexity Affecting openssl package, versions <1.0.2g-1ubuntu4.20+esm10
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-UBUNTU1604-OPENSSL-5786293
- published19 Jul 2023
- disclosed19 Jul 2023
Introduced: 19 Jul 2023
CVE-2023-3446 (opens in a new tab)How to fix?
Upgrade Ubuntu:16.04 openssl to version 1.0.2g-1ubuntu4.20+esm10 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream openssl package and not the openssl package as distributed by Ubuntu.
See How to fix? for Ubuntu:16.04 relevant fixed versions and status.
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. One of those checks confirms that the modulus ('p' parameter) is not too large. Trying to use a very large modulus is slow and OpenSSL will not normally use a modulus which is over 10,000 bits in length.
However the DH_check() function checks numerous aspects of the key or parameters that have been supplied. Some of those checks use the supplied modulus value even if it has already been found to be too large.
An application that calls DH_check() and supplies a key or parameters obtained from an untrusted source could be vulernable 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.
References
- http://people.ubuntu.com/~ubuntu-security/cve/CVE-2023-3446
- http://www.openwall.com/lists/oss-security/2023/07/19/4
- http://www.openwall.com/lists/oss-security/2023/07/19/5
- http://www.openwall.com/lists/oss-security/2023/07/19/6
- http://www.openwall.com/lists/oss-security/2023/07/31/1
- http://www.openwall.com/lists/oss-security/2024/05/16/1
- https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=1fa20cf2f506113c761777127a38bce5068740eb
- https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=8780a896543a654e757db1b9396383f9d8095528
- https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=9a0a4d3c1e7138915563c0df4fe6a3f9377b839c
- https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=fc9867c1e03c22ebf56943be205202e576aabf23
- https://lists.debian.org/debian-lts-announce/2023/08/msg00019.html
- https://security.gentoo.org/glsa/202402-08
- https://security.netapp.com/advisory/ntap-20230803-0011/
- https://www.openssl.org/news/secadv/20230719.txt