Amazon Linux 2 Security Advisory: ALAS-2023-2205
Advisory Release Date: 2023-08-17 11:58 Pacific
Advisory Updated Date: 2023-08-23 00:19 Pacific
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. (CVE-2023-3817)
Affected Packages:
edk2
Note:
This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.
Issue Correction:
Run yum update edk2 to update your system.
aarch64:
edk2-tools-20200801stable-1.amzn2.0.2.aarch64
edk2-debuginfo-20200801stable-1.amzn2.0.2.aarch64
noarch:
edk2-tools-python-20200801stable-1.amzn2.0.2.noarch
edk2-tools-doc-20200801stable-1.amzn2.0.2.noarch
edk2-ovmf-20200801stable-1.amzn2.0.2.noarch
edk2-aarch64-20200801stable-1.amzn2.0.2.noarch
src:
edk2-20200801stable-1.amzn2.0.2.src
x86_64:
edk2-tools-20200801stable-1.amzn2.0.2.x86_64
edk2-debuginfo-20200801stable-1.amzn2.0.2.x86_64