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news/changes: fix formatting nits 

The news/changes files are being nitted causing CI failure.  This addresses the
issues.

Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/16413)
This commit is contained in:
Pauli 2021-08-25 10:44:01 +10:00
parent e1c2913833
commit fdd436436d
2 changed files with 54 additions and 47 deletions
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100
CHANGES.md
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@ -1362,66 +1362,72 @@ OpenSSL 1.1.1
* Fixed an SM2 Decryption Buffer Overflow.
In order to decrypt SM2 encrypted data an application is expected to call the
API function EVP_PKEY_decrypt(). Typically an application will call this
function twice. The first time, on entry, the "out" parameter can be NULL and,
on exit, the "outlen" parameter is populated with the buffer size required to
hold the decrypted plaintext. The application can then allocate a sufficiently
sized buffer and call EVP_PKEY_decrypt() again, but this time passing a non-NULL
value for the "out" parameter.
In order to decrypt SM2 encrypted data an application is expected to
call the API function EVP_PKEY_decrypt(). Typically an application will
call this function twice. The first time, on entry, the "out" parameter
can be NULL and, on exit, the "outlen" parameter is populated with the
buffer size required to hold the decrypted plaintext. The application
can then allocate a sufficiently sized buffer and call EVP_PKEY_decrypt()
again, but this time passing a non-NULL value for the "out" parameter.
A bug in the implementation of the SM2 decryption code means that the
calculation of the buffer size required to hold the plaintext returned by the
first call to EVP_PKEY_decrypt() can be smaller than the actual size required by
the second call. This can lead to a buffer overflow when EVP_PKEY_decrypt() is
called by the application a second time with a buffer that is too small.
calculation of the buffer size required to hold the plaintext returned
by the first call to EVP_PKEY_decrypt() can be smaller than the actual
size required by the second call. This can lead to a buffer overflow
when EVP_PKEY_decrypt() is called by the application a second time with
a buffer that is too small.
A malicious attacker who is able present SM2 content for decryption to an
application could cause attacker chosen data to overflow the buffer by up to a
maximum of 62 bytes altering the contents of other data held after the
buffer, possibly changing application behaviour or causing the application to
crash. The location of the buffer is application dependent but is typically
heap allocated.
A malicious attacker who is able present SM2 content for decryption to
an application could cause attacker chosen data to overflow the buffer
by up to a maximum of 62 bytes altering the contents of other data held
after the buffer, possibly changing application behaviour or causing
the application to crash. The location of the buffer is application
dependent but is typically heap allocated.
([CVE-2021-3711])
*Matt Caswell*
* Fixed various read buffer overruns processing ASN.1 strings
* Fixed various read buffer overruns processing ASN.1 strings
ASN.1 strings are represented internally within OpenSSL as an ASN1_STRING
structure which contains a buffer holding the string data and a field holding
the buffer length. This contrasts with normal C strings which are repesented as
a buffer for the string data which is terminated with a NUL (0) byte.
ASN.1 strings are represented internally within OpenSSL as an ASN1_STRING
structure which contains a buffer holding the string data and a field
holding the buffer length. This contrasts with normal C strings which
are repesented as a buffer for the string data which is terminated
with a NUL (0) byte.
Although not a strict requirement, ASN.1 strings that are parsed using OpenSSL's
own "d2i" functions (and other similar parsing functions) as well as any string
whose value has been set with the ASN1_STRING_set() function will additionally
NUL terminate the byte array in the ASN1_STRING structure.
Although not a strict requirement, ASN.1 strings that are parsed using
OpenSSL's own "d2i" functions (and other similar parsing functions) as
well as any string whose value has been set with the ASN1_STRING_set()
function will additionally NUL terminate the byte array in the
ASN1_STRING structure.
However, it is possible for applications to directly construct valid ASN1_STRING
structures which do not NUL terminate the byte array by directly setting the
"data" and "length" fields in the ASN1_STRING array. This can also happen by
using the ASN1_STRING_set0() function.
However, it is possible for applications to directly construct valid
ASN1_STRING structures which do not NUL terminate the byte array by
directly setting the "data" and "length" fields in the ASN1_STRING
array. This can also happen by using the ASN1_STRING_set0() function.
Numerous OpenSSL functions that print ASN.1 data have been found to assume that
the ASN1_STRING byte array will be NUL terminated, even though this is not
guaranteed for strings that have been directly constructed. Where an application
requests an ASN.1 structure to be printed, and where that ASN.1 structure
contains ASN1_STRINGs that have been directly constructed by the application
without NUL terminating the "data" field, then a read buffer overrun can occur.
Numerous OpenSSL functions that print ASN.1 data have been found to
assume that the ASN1_STRING byte array will be NUL terminated, even
though this is not guaranteed for strings that have been directly
constructed. Where an application requests an ASN.1 structure to be
printed, and where that ASN.1 structure contains ASN1_STRINGs that have
been directly constructed by the application without NUL terminating
the "data" field, then a read buffer overrun can occur.
The same thing can also occur during name constraints processing of certificates
(for example if a certificate has been directly constructed by the application
instead of loading it via the OpenSSL parsing functions, and the certificate
contains non NUL terminated ASN1_STRING structures). It can also occur in the
X509_get1_email(), X509_REQ_get1_email() and X509_get1_ocsp() functions.
The same thing can also occur during name constraints processing
of certificates (for example if a certificate has been directly
constructed by the application instead of loading it via the OpenSSL
parsing functions, and the certificate contains non NUL terminated
ASN1_STRING structures). It can also occur in the X509_get1_email(),
X509_REQ_get1_email() and X509_get1_ocsp() functions.
If a malicious actor can cause an application to directly construct an
ASN1_STRING and then process it through one of the affected OpenSSL functions
then this issue could be hit. This might result in a crash (causing a Denial of
Service attack). It could also result in the disclosure of private memory
contents (such as private keys, or sensitive plaintext).
([CVE-2021-3712])
If a malicious actor can cause an application to directly construct an
ASN1_STRING and then process it through one of the affected OpenSSL
functions then this issue could be hit. This might result in a crash
(causing a Denial of Service attack). It could also result in the
disclosure of private memory contents (such as private keys, or
sensitive plaintext).
([CVE-2021-3712])
*Matt Caswell*

1
NEWS.md
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@ -90,6 +90,7 @@ OpenSSL 1.1.1
-------------
### Major changes between OpenSSL 1.1.1k and OpenSSL 1.1.1l [24 Aug 2021]
* Fixed an SM2 Decryption Buffer Overflow ([CVE-2021-3711])
* Fixed various read buffer overruns processing ASN.1 strings ([CVE-2021-3712])