| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| Buffer overflows in OpenSSL 0.9.6d and earlier, and 0.9.7-beta2 and earlier, allow remote attackers to execute arbitrary code via (1) a large client master key in SSL2 or (2) a large session ID in SSL3. |
| ssl3_get_record in s3_pkt.c for OpenSSL before 0.9.7a and 0.9.6 before 0.9.6i does not perform a MAC computation if an incorrect block cipher padding is used, which causes an information leak (timing discrepancy) that may make it easier to launch cryptographic attacks that rely on distinguishing between padding and MAC verification errors, possibly leading to extraction of the original plaintext, aka the "Vaudenay timing attack." |
| Integer overflow in OpenSSL 0.9.6 and 0.9.7 allows remote attackers to cause a denial of service (crash) via an SSL client certificate with certain ASN.1 tag values. |
| OpenSSL 0.9.6 and 0.9.7 does not properly track the number of characters in certain ASN.1 inputs, which allows remote attackers to cause a denial of service (crash) via an SSL client certificate that causes OpenSSL to read past the end of a buffer when the long form is used. |
| The der_chop script in the openssl package in Trustix Secure Linux 1.5 through 2.1 and other operating systems allows local users to overwrite files via a symlink attack on temporary files. |
| OpenSSL does not use RSA blinding by default, which allows local and remote attackers to obtain the server's private key by determining factors using timing differences on (1) the number of extra reductions during Montgomery reduction, and (2) the use of different integer multiplication algorithms ("Karatsuba" and normal). |
| OpenSSL and SSLeay allow remote attackers to reuse SSL sessions and bypass access controls. |
| OpenSSL 0.9.4 and OpenSSH for FreeBSD do not properly check for the existence of the /dev/random or /dev/urandom devices, which are absent on FreeBSD Alpha systems, which causes them to produce weak keys which may be more easily broken. |
| The SSL and TLS components for OpenSSL 0.9.6i and earlier, 0.9.7, and 0.9.7a allow remote attackers to perform an unauthorized RSA private key operation via a modified Bleichenbacher attack that uses a large number of SSL or TLS connections using PKCS #1 v1.5 padding that cause OpenSSL to leak information regarding the relationship between ciphertext and the associated plaintext, aka the "Klima-Pokorny-Rosa attack." |
| The ASN1 library in OpenSSL 0.9.6d and earlier, and 0.9.7-beta2 and earlier, allows remote attackers to cause a denial of service via invalid encodings. |
| 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. |
| Issue summary: Processing some specially crafted ASN.1 object identifiers or
data containing them may be very slow.
Impact summary: Applications that use OBJ_obj2txt() directly, or use any of
the OpenSSL subsystems OCSP, PKCS7/SMIME, CMS, CMP/CRMF or TS with no message
size limit may experience notable to very long delays when processing those
messages, which may lead to a Denial of Service.
An OBJECT IDENTIFIER is composed of a series of numbers - sub-identifiers -
most of which have no size limit. OBJ_obj2txt() may be used to translate
an ASN.1 OBJECT IDENTIFIER given in DER encoding form (using the OpenSSL
type ASN1_OBJECT) to its canonical numeric text form, which are the
sub-identifiers of the OBJECT IDENTIFIER in decimal form, separated by
periods.
When one of the sub-identifiers in the OBJECT IDENTIFIER is very large
(these are sizes that are seen as absurdly large, taking up tens or hundreds
of KiBs), the translation to a decimal number in text may take a very long
time. The time complexity is O(n^2) with 'n' being the size of the
sub-identifiers in bytes (*).
With OpenSSL 3.0, support to fetch cryptographic algorithms using names /
identifiers in string form was introduced. This includes using OBJECT
IDENTIFIERs in canonical numeric text form as identifiers for fetching
algorithms.
Such OBJECT IDENTIFIERs may be received through the ASN.1 structure
AlgorithmIdentifier, which is commonly used in multiple protocols to specify
what cryptographic algorithm should be used to sign or verify, encrypt or
decrypt, or digest passed data.
Applications that call OBJ_obj2txt() directly with untrusted data are
affected, with any version of OpenSSL. If the use is for the mere purpose
of display, the severity is considered low.
In OpenSSL 3.0 and newer, this affects the subsystems OCSP, PKCS7/SMIME,
CMS, CMP/CRMF or TS. It also impacts anything that processes X.509
certificates, including simple things like verifying its signature.
The impact on TLS is relatively low, because all versions of OpenSSL have a
100KiB limit on the peer's certificate chain. Additionally, this only
impacts clients, or servers that have explicitly enabled client
authentication.
In OpenSSL 1.1.1 and 1.0.2, this only affects displaying diverse objects,
such as X.509 certificates. This is assumed to not happen in such a way
that it would cause a Denial of Service, so these versions are considered
not affected by this issue in such a way that it would be cause for concern,
and the severity is therefore considered low. |
| 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. |
| 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. |
| Issue summary: The AES-XTS cipher decryption implementation for 64 bit ARM
platform contains a bug that could cause it to read past the input buffer,
leading to a crash.
Impact summary: Applications that use the AES-XTS algorithm on the 64 bit ARM
platform can crash in rare circumstances. The AES-XTS algorithm is usually
used for disk encryption.
The AES-XTS cipher decryption implementation for 64 bit ARM platform will read
past the end of the ciphertext buffer if the ciphertext size is 4 mod 5 in 16
byte blocks, e.g. 144 bytes or 1024 bytes. If the memory after the ciphertext
buffer is unmapped, this will trigger a crash which results in a denial of
service.
If an attacker can control the size and location of the ciphertext buffer
being decrypted by an application using AES-XTS on 64 bit ARM, the
application is affected. This is fairly unlikely making this issue
a Low severity one. |
| Issue summary: Checking excessively long DSA keys or parameters may be very
slow.
Impact summary: Applications that use the functions EVP_PKEY_param_check()
or EVP_PKEY_public_check() to check a DSA public key or DSA 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 functions EVP_PKEY_param_check() or EVP_PKEY_public_check() perform
various checks on DSA parameters. Some of those computations take a long time
if the modulus (`p` parameter) is too large.
Trying to use a very large modulus is slow and OpenSSL will not allow using
public keys with a modulus which is over 10,000 bits in length for signature
verification. However the key and parameter check functions do not limit
the modulus size when performing the checks.
An application that calls EVP_PKEY_param_check() or EVP_PKEY_public_check()
and supplies a key or parameters obtained from an untrusted source could be
vulnerable to a Denial of Service attack.
These functions are not called by OpenSSL itself on untrusted DSA keys so
only applications that directly call these functions may be vulnerable.
Also vulnerable are the OpenSSL pkey 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 affected by this issue. |
| 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() doesn't 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 doesn't 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. |
| Issue summary: A bug has been identified in the processing of key and
initialisation vector (IV) lengths. This can lead to potential truncation
or overruns during the initialisation of some symmetric ciphers.
Impact summary: A truncation in the IV can result in non-uniqueness,
which could result in loss of confidentiality for some cipher modes.
When calling EVP_EncryptInit_ex2(), EVP_DecryptInit_ex2() or
EVP_CipherInit_ex2() the provided OSSL_PARAM array is processed after
the key and IV have been established. Any alterations to the key length,
via the "keylen" parameter or the IV length, via the "ivlen" parameter,
within the OSSL_PARAM array will not take effect as intended, potentially
causing truncation or overreading of these values. The following ciphers
and cipher modes are impacted: RC2, RC4, RC5, CCM, GCM and OCB.
For the CCM, GCM and OCB cipher modes, truncation of the IV can result in
loss of confidentiality. For example, when following NIST's SP 800-38D
section 8.2.1 guidance for constructing a deterministic IV for AES in
GCM mode, truncation of the counter portion could lead to IV reuse.
Both truncations and overruns of the key and overruns of the IV will
produce incorrect results and could, in some cases, trigger a memory
exception. However, these issues are not currently assessed as security
critical.
Changing the key and/or IV lengths is not considered to be a common operation
and the vulnerable API was recently introduced. Furthermore it is likely that
application developers will have spotted this problem during testing since
decryption would fail unless both peers in the communication were similarly
vulnerable. For these reasons we expect the probability of an application being
vulnerable to this to be quite low. However if an application is vulnerable then
this issue is considered very serious. For these reasons we have assessed this
issue as Moderate severity overall.
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 because
the issue lies outside of the FIPS provider boundary.
OpenSSL 3.1 and 3.0 are vulnerable to this issue. |
| If an X.509 certificate contains a malformed policy constraint and
policy processing is enabled, then a write lock will be taken twice
recursively. On some operating systems (most widely: Windows) this
results in a denial of service when the affected process hangs. Policy
processing being enabled on a publicly facing server is not considered
to be a common setup.
Policy processing is enabled by passing the `-policy'
argument to the command line utilities or by calling the
`X509_VERIFY_PARAM_set1_policies()' function.
Update (31 March 2023): The description of the policy processing enablement
was corrected based on CVE-2023-0466. |
| OpenSSL supports creating a custom cipher via the legacy EVP_CIPHER_meth_new() function and associated function calls. This function was deprecated in OpenSSL 3.0 and application authors are instead encouraged to use the new provider mechanism in order to implement custom ciphers. OpenSSL versions 3.0.0 to 3.0.5 incorrectly handle legacy custom ciphers passed to the EVP_EncryptInit_ex2(), EVP_DecryptInit_ex2() and EVP_CipherInit_ex2() functions (as well as other similarly named encryption and decryption initialisation functions). Instead of using the custom cipher directly it incorrectly tries to fetch an equivalent cipher from the available providers. An equivalent cipher is found based on the NID passed to EVP_CIPHER_meth_new(). This NID is supposed to represent the unique NID for a given cipher. However it is possible for an application to incorrectly pass NID_undef as this value in the call to EVP_CIPHER_meth_new(). When NID_undef is used in this way the OpenSSL encryption/decryption initialisation function will match the NULL cipher as being equivalent and will fetch this from the available providers. This will succeed if the default provider has been loaded (or if a third party provider has been loaded that offers this cipher). Using the NULL cipher means that the plaintext is emitted as the ciphertext. Applications are only affected by this issue if they call EVP_CIPHER_meth_new() using NID_undef and subsequently use it in a call to an encryption/decryption initialisation function. Applications that only use SSL/TLS are not impacted by this issue. Fixed in OpenSSL 3.0.6 (Affected 3.0.0-3.0.5). |
