Advisories ยป MGASA-2023-0130

Updated openssl packages fix security vulnerability

Publication date: 11 Apr 2023
Type: security
Affected Mageia releases : 8
CVE: CVE-2022-4203 , CVE-2022-4304 , CVE-2022-4450 , CVE-2023-0215 , CVE-2023-0216 , CVE-2023-0217 , CVE-2023-0286 , CVE-2023-0401 , CVE-2023-0464 , CVE-2023-0465 , CVE-2023-0466


A read buffer overrun can be triggered in X.509 certificate verification,
specifically in name constraint checking. Note that this occurs after
certificate chain signature verification and requires either a CA to have
signed the malicious certificate or for the application to continue
certificate verification despite failure to construct a path to a trusted
issuer. The read buffer overrun might result in a crash which could lead
to a denial of service attack. In theory it could also result in the
disclosure of private memory contents (such as private keys, or sensitive
plaintext) although we are not aware of any working exploit leading to
memory contents disclosure as of the time of release of this advisory. In
a TLS client, this can be triggered by connecting to a malicious server.
In a TLS server, this can be triggered if the server requests client
authentication and a malicious client connects. (CVE-2022-4203)

A timing based side channel exists in the OpenSSL RSA Decryption
implementation which could be sufficient to recover a plaintext across a
network in a Bleichenbacher style attack. To achieve a successful
decryption an attacker would have to be able to send a very large number
of trial messages for decryption. The vulnerability affects all RSA
padding modes: PKCS#1 v1.5, RSA-OEAP and RSASVE. For example, in a TLS
connection, RSA is commonly used by a client to send an encrypted
pre-master secret to the server. An attacker that had observed a genuine
connection between a client and a server could use this flaw to send trial
messages to the server and record the time taken to process them. After a
sufficiently large number of messages the attacker could recover the
pre-master secret used for the original connection and thus be able to
decrypt the application data sent over that connection. (CVE-2022-4304)

The function PEM_read_bio_ex() reads a PEM file from a BIO and parses and
decodes the "name" (e.g. "CERTIFICATE"), any header data and the payload
data. If the function succeeds then the "name_out", "header" and "data"
arguments are populated with pointers to buffers containing the relevant
decoded data. The caller is responsible for freeing those buffers. It is
possible to construct a PEM file that results in 0 bytes of payload data.
In this case PEM_read_bio_ex() will return a failure code but will
populate the header argument with a pointer to a buffer that has already
been freed. If the caller also frees this buffer then a double free will
occur. This will most likely lead to a crash. This could be exploited by
an attacker who has the ability to supply malicious PEM files for parsing
to achieve a denial of service attack. The functions PEM_read_bio() and
PEM_read() are simple wrappers around PEM_read_bio_ex() and therefore
these functions are also directly affected. These functions are also
called indirectly by a number of other OpenSSL functions including
PEM_X509_INFO_read_bio_ex() and SSL_CTX_use_serverinfo_file() which are
also vulnerable. Some OpenSSL internal uses of these functions are not
vulnerable because the caller does not free the header argument if
PEM_read_bio_ex() returns a failure code. These locations include the
PEM_read_bio_TYPE() functions as well as the decoders introduced in
OpenSSL 3.0. The OpenSSL asn1parse command line application is also
impacted by this issue. (CVE-2022-4450)

The public API function BIO_new_NDEF is a helper function used for
streaming ASN.1 data via a BIO. It is primarily used internally to OpenSSL
to support the SMIME, CMS and PKCS7 streaming capabilities, but may also
be called directly by end user applications. The function receives a BIO
from the caller, prepends a new BIO_f_asn1 filter BIO onto the front of it
to form a BIO chain, and then returns the new head of the BIO chain to the
caller. Under certain conditions, for example if a CMS recipient public
key is invalid, the new filter BIO is freed and the function returns a
NULL result indicating a failure. However, in this case, the BIO chain is
not properly cleaned up and the BIO passed by the caller still retains
internal pointers to the previously freed filter BIO. If the caller then
goes on to call BIO_pop() on the BIO then a use-after-free will occur.
This will most likely result in a crash. This scenario occurs directly in
the internal function B64_write_ASN1() which may cause BIO_new_NDEF() to
be called and will subsequently call BIO_pop() on the BIO. This internal
function is in turn called by the public API functions
PEM_write_bio_ASN1_stream, PEM_write_bio_CMS_stream,
PEM_write_bio_PKCS7_stream, SMIME_write_ASN1, SMIME_write_CMS and
SMIME_write_PKCS7. Other public API functions that may be impacted by this
include i2d_ASN1_bio_stream, BIO_new_CMS, BIO_new_PKCS7,
i2d_CMS_bio_stream and i2d_PKCS7_bio_stream. The OpenSSL cms and smime
command line applications are similarly affected. (CVE-2023-0215)

An invalid pointer dereference on read can be triggered when an
application tries to load malformed PKCS7 data with the d2i_PKCS7(),
d2i_PKCS7_bio() or d2i_PKCS7_fp() functions. The result of the dereference
is an application crash which could lead to a denial of service attack.
The TLS implementation in OpenSSL does not call this function however
third party applications might call these functions on untrusted data.

An invalid pointer dereference on read can be triggered when an
application tries to check a malformed DSA public key by the
EVP_PKEY_public_check() function. This will most likely lead to an
application crash. This function can be called on public keys supplied
from untrusted sources which could allow an attacker to cause a denial of
service attack. The TLS implementation in OpenSSL does not call this
function but applications might call the function if there are additional
security requirements imposed by standards such as FIPS 140-3.

There is a type confusion vulnerability relating to X.400 address
processing inside an X.509 GeneralName. X.400 addresses were parsed as an
ASN1_STRING but the public structure definition for GENERAL_NAME
incorrectly specified the type of the x400Address field as ASN1_TYPE. This
field is subsequently interpreted by the OpenSSL function GENERAL_NAME_cmp
as an ASN1_TYPE rather than an ASN1_STRING. When CRL checking is enabled
(i.e. the application sets the X509_V_FLAG_CRL_CHECK flag), this
vulnerability may allow an attacker to pass arbitrary pointers to a memcmp
call, enabling them to read memory contents or enact a denial of service.
In most cases, the attack requires the attacker to provide both the
certificate chain and CRL, neither of which need to have a valid
signature. If the attacker only controls one of these inputs, the other
input must already contain an X.400 address as a CRL distribution point,
which is uncommon. As such, this vulnerability is most likely to only
affect applications which have implemented their own functionality for
retrieving CRLs over a network. (CVE-2023-0286)

A NULL pointer can be dereferenced when signatures are being verified on
PKCS7 signed or signedAndEnveloped data. In case the hash algorithm used
for the signature is known to the OpenSSL library but the implementation
of the hash algorithm is not available the digest initialization will
fail. There is a missing check for the return value from the
initialization function which later leads to invalid usage of the digest
API most likely leading to a crash. The unavailability of an algorithm can
be caused by using FIPS enabled configuration of providers or more
commonly by not loading the legacy provider. PKCS7 data is processed by
the SMIME library calls and also by the time stamp (TS) library calls. The
TLS implementation in OpenSSL does not call these functions however third
party applications would be affected if they call these functions to
verify signatures on untrusted data. (CVE-2023-0401)

A security vulnerability has been identified in all supported versions of
OpenSSL related to the verification of X.509 certificate chains that
include policy constraints. Attackers may be able to exploit this
vulnerability by creating a malicious certificate chain that triggers
exponential use of computational resources, leading to a denial-of-service
(DoS) attack on affected systems. Policy processing is disabled by default
but can be enabled by passing the `-policy' argument to the command line
utilities or by calling the `X509_VERIFY_PARAM_set1_policies()' function.

Applications that use a non-default option when verifying certificates may
be vulnerable to an attack from a malicious CA to circumvent certain
checks. Invalid certificate policies in leaf certificates are silently
ignored by OpenSSL and other certificate policy checks are skipped for
that certificate. A malicious CA could use this to deliberately assert
invalid certificate policies in order to circumvent policy checking on the
certificate altogether. Policy processing is disabled by default but can
be enabled by passing the `-policy' argument to the command line utilities
or by calling the `X509_VERIFY_PARAM_set1_policies()' function. (CVE-2023-0465)

The function X509_VERIFY_PARAM_add0_policy() is documented to implicitly
enable the certificate policy check when doing certificate verification.
However the implementation of the function does not enable the check which
allows certificates with invalid or incorrect policies to pass the
certificate verification. As suddenly enabling the policy check could
break existing deployments it was decided to keep the existing behavior of
the X509_VERIFY_PARAM_add0_policy() function. Instead the applications
that require OpenSSL to perform certificate policy check need to use
X509_VERIFY_PARAM_set1_policies() or explicitly enable the policy check by
calling X509_VERIFY_PARAM_set_flags() with the X509_V_FLAG_POLICY_CHECK
flag argument. Certificate policy checks are disabled by default in
OpenSSL and are not commonly used by applications. (CVE-2023-0466)