https://github.com/openssl/openssl/commits/ and pick the appropriate

release branch.

Changes between 1.1.1j and 1.1.1k [25 Mar 2021]

*) Fixed a problem with verifying a certificate chain when using the

X509_V_FLAG_X509_STRICT flag. This flag enables additional security checks

of the certificates present in a certificate chain. It is not set by

default.

Starting from OpenSSL version 1.1.1h a check to disallow certificates in

the chain that have explicitly encoded elliptic curve parameters was added

as an additional strict check.

An error in the implementation of this check meant that the result of a

previous check to confirm that certificates in the chain are valid CA

certificates was overwritten. This effectively bypasses the check

that non-CA certificates must not be able to issue other certificates.

If a "purpose" has been configured then there is a subsequent opportunity

for checks that the certificate is a valid CA. All of the named "purpose"

values implemented in libcrypto perform this check. Therefore, where

a purpose is set the certificate chain will still be rejected even when the

strict flag has been used. A purpose is set by default in libssl client and

server certificate verification routines, but it can be overridden or

removed by an application.

In order to be affected, an application must explicitly set the

X509_V_FLAG_X509_STRICT verification flag and either not set a purpose

for the certificate verification or, in the case of TLS client or server

applications, override the default purpose.

(CVE-2021-3450)

[Tomáš Mráz]

*) Fixed an issue where an OpenSSL TLS server may crash if sent a maliciously

crafted renegotiation ClientHello message from a client. If a TLSv1.2

renegotiation ClientHello omits the signature_algorithms extension (where

it was present in the initial ClientHello), but includes a

signature_algorithms_cert extension then a NULL pointer dereference will

result, leading to a crash and a denial of service attack.

A server is only vulnerable if it has TLSv1.2 and renegotiation enabled

(which is the default configuration). OpenSSL TLS clients are not impacted

by this issue.

(CVE-2021-3449)

[Peter Kästle and Samuel Sapalski]

Changes between 1.1.1i and 1.1.1j [16 Feb 2021]

*) Fixed the X509_issuer_and_serial_hash() function. It attempts to