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Diffstat (limited to 'Changes.rst')
| -rw-r--r-- | Changes.rst | 143 |
1 files changed, 2 insertions, 141 deletions
diff --git a/Changes.rst b/Changes.rst index 454dde4..7ffd89e 100644 --- a/Changes.rst +++ b/Changes.rst @@ -1,5 +1,5 @@ -Overview of changes in 2.4 -========================== +Version 2.4.0 +============= New features @@ -177,7 +177,6 @@ Deprecated features - ``--no-iv`` is deprecated in 2.4 and will be removed in 2.5. - User-visible Changes -------------------- - When using ciphers with cipher blocks less than 128-bits, @@ -303,141 +302,3 @@ Maintainer-visible changes header combinations. In most of these situations it is recommended to use -std=gnu99 in CFLAGS. This is known to be needed when doing i386/i686 builds on RHEL5. - - - -Version 2.4.3 -============= - -New features ------------- -- Support building with OpenSSL 1.1 now (in addition to older versions) - -- On Win10, set low interface metric for TAP adapter when block-outside-dns - is in use, to make Windows prefer the TAP adapter for DNS queries - (avoiding large delays) - - -Security --------- -- CVE-2017-7522: Fix ``--x509-track`` post-authentication remote DoS - A client could crash a 2.4+ mbedtls server, if that server uses the - ``--x509-track`` option and the client has a correct, signed and unrevoked - certificate that contains an embedded NUL in the certificate subject. - Discovered and reported to the OpenVPN security team by Guido Vranken. - -- CVE-2017-7521: Fix post-authentication remote-triggerable memory leaks - A client could cause a server to leak a few bytes each time it connects to the - server. That can eventuall cause the server to run out of memory, and thereby - causing the server process to terminate. Discovered and reported to the - OpenVPN security team by Guido Vranken. (OpenSSL builds only.) - -- CVE-2017-7521: Fix a potential post-authentication remote code execution - attack on servers that use the ``--x509-username-field`` option with an X.509 - extension field (option argument prefixed with ``ext:``). A client that can - cause a server to run out-of-memory (see above) might be able to cause the - server to double free, which in turn might lead to remote code execution. - Discovered and reported to the OpenVPN security team by Guido Vranken. - (OpenSSL builds only.) - -- CVE-2017-7520: Pre-authentication remote crash/information disclosure for - clients. If clients use a HTTP proxy with NTLM authentication (i.e. - ``--http-proxy <server> <port> [<authfile>|'auto'|'auto-nct'] ntlm2``), - a man-in-the-middle attacker between the client and the proxy can cause - the client to crash or disclose at most 96 bytes of stack memory. The - disclosed stack memory is likely to contain the proxy password. If the - proxy password is not reused, this is unlikely to compromise the security - of the OpenVPN tunnel itself. Clients who do not use the ``--http-proxy`` - option with ntlm2 authentication are not affected. - -- CVE-2017-7508: Fix remotely-triggerable ASSERT() on malformed IPv6 packet. - This can be used to remotely shutdown an openvpn server or client, if - IPv6 and ``--mssfix`` are enabled and the IPv6 networks used inside the VPN - are known. - -- Fix null-pointer dereference when talking to a malicious http proxy - that returns a malformed Proxy-Authenticate: headers for digest auth. - -- Fix overflow check for long ``--tls-cipher`` option - -- Windows: Pass correct buffer size to ``GetModuleFileNameW()`` - (OSTIF/Quarkslabs audit, finding 5.6) - - -User-visible Changes --------------------- -- ``--verify-hash`` can now take an optional flag which changes the hashing - algorithm. It can be either SHA1 or SHA256. The default if not provided is - SHA1 to preserve backwards compatibility with existing configurations. - -- Restrict the supported ``--x509-username-field`` extension fields to subjectAltName - and issuerAltName. Other extensions probably didn't work anyway, and would - cause OpenVPN to crash when a client connects. - - -Bugfixes --------- -- Fix fingerprint calculation in mbed TLS builds. This means that mbed TLS users - of OpenVPN 2.4.0, 2.4.1 and 2.4.2 that rely on the values of the - ``tls_digest_*`` env vars, or that use ``--verify-hash`` will have to change - the fingerprint values they check against. The security impact of the - incorrect calculation is very minimal; the last few bytes (max 4, typically - 4) are not verified by the fingerprint. We expect no real-world impact, - because users that used this feature before will notice that it has suddenly - stopped working, and users that didn't will notice that connection setup - fails if they specify correct fingerprints. - -- Fix edge case with NCP when the server sends an empty PUSH_REPLY message - back, and the client would not initialize it's data channel crypto layer - properly (trac #903) - -- Fix SIGSEGV on unaligned buffer access on OpenBSD/Sparc64 - -- Fix TCP_NODELAY on OpenBSD - -- Remove erroneous limitation on max number of args for --plugin - -- Fix NCP behaviour on TLS reconnect (Server would not send a proper - "cipher ..." message back to the client, leading to client and server - using different ciphers) (trac #887) - - -Version 2.4.2 -============= - -Bugfixes --------- -- Fix memory leak introduced in 2.4.1: if --remote-cert-tls is used, we leaked - some memory on each TLS (re)negotiation. - -Security --------- -- Fix a pre-authentication denial-of-service attack on both clients and servers. - By sending a too-large control packet, OpenVPN 2.4.0 or 2.4.1 can be forced - to hit an ASSERT() and stop the process. If ``--tls-auth`` or ``--tls-crypt`` - is used, only attackers that have the ``--tls-auth`` or ``--tls-crypt`` key - can mount an attack. (OSTIF/Quarkslab audit finding 5.1, CVE-2017-7478) - -- Fix an authenticated remote DoS vulnerability that could be triggered by - causing a packet id roll over. An attack is rather inefficient; a peer - would need to get us to send at least about 196 GB of data. - (OSTIF/Quarkslab audit finding 5.2, CVE-2017-7479) - - -Version 2.4.1 -============= -- ``--remote-cert-ku`` now only requires the certificate to have at least the - bits set of one of the values in the supplied list, instead of requiring an - exact match to one of the values in the list. - -- ``--remote-cert-tls`` now only requires that a keyUsage is present in the - certificate, and leaves the verification of the value up to the crypto - library, which has more information (i.e. the key exchange method in use) - to verify that the keyUsage is correct. - -- ``--ns-cert-type`` is deprecated. Use ``--remote-cert-tls`` instead. - The nsCertType x509 extension is very old, and barely used. - ``--remote-cert-tls`` uses the far more common keyUsage and extendedKeyUsage - extension instead. Make sure your certificates carry these to be able to - use ``--remote-cert-tls``. - |