Package Instance

Improper Check for Unusual or Exceptional Conditions
Issue summary: Generating excessively long X9.42 DH keys or checking
excessively long X9.42 DH keys or parameters may be very slow.

Impact summary: Applications that use the functions DH_generate_key() to
generate an X9.42 DH key may experience long delays. Likewise, applications
that use DH_check_pub_key(), DH_check_pub_key_ex() or EVP_PKEY_public_check()
to check an X9.42 DH key or X9.42 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.

While DH_check() performs all the necessary checks (as of CVE-2023-3817),
DH_check_pub_key() does not make any of these checks, and is therefore
vulnerable for excessively large P and Q parameters.

Likewise, while DH_generate_key() performs a check for an excessively large
P, it does not check for an excessively large Q.

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

DH_generate_key() and DH_check_pub_key() are also 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_pub_key_ex(), EVP_PKEY_public_check(), and EVP_PKEY_generate().

Also vulnerable are the OpenSSL pkey command line application when using the
"-pubcheck" option, as well as the OpenSSL genpkey command line application.

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.

Inefficient Regular Expression Complexity
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.

Excessive Iteration
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.