Summary
Package updates are available for Amazon Linux 2 that fix the following vulnerabilities: 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.
Fixed packages 6
| Release | Package | Fixed in |
|---|---|---|
| Amazon Linux · 2 | edk2-aarch64 | 0:20200801stable-1.amzn2.0.2 |
| Amazon Linux · 2 | edk2-debuginfo | 0:20200801stable-1.amzn2.0.2 |
| Amazon Linux · 2 | edk2-ovmf | 0:20200801stable-1.amzn2.0.2 |
| Amazon Linux · 2 | edk2-tools | 0:20200801stable-1.amzn2.0.2 |
| Amazon Linux · 2 | edk2-tools-doc | 0:20200801stable-1.amzn2.0.2 |
| Amazon Linux · 2 | edk2-tools-python | 0:20200801stable-1.amzn2.0.2 |
Vulnerabilities 1
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Medium 5.3
Excessive time spent checking DH q parameter value
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 k…
References
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web
https://alas.aws.amazon.com/cve/html/CVE-2023-3817.html