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-rw-r--r-- | CHANGES | 64 | ||||
-rw-r--r-- | NEWS | 7 |
2 files changed, 70 insertions, 1 deletions
@@ -4,6 +4,70 @@ Changes between 1.1.0 and 1.1.0a [xx XXX xxxx] + *) OCSP Status Request extension unbounded memory growth + + A malicious client can send an excessively large OCSP Status Request + extension. If that client continually requests renegotiation, sending a + large OCSP Status Request extension each time, then there will be unbounded + memory growth on the server. This will eventually lead to a Denial Of + Service attack through memory exhaustion. Servers with a default + configuration are vulnerable even if they do not support OCSP. Builds using + the "no-ocsp" build time option are not affected. + + This issue was reported to OpenSSL by Shi Lei (Gear Team, Qihoo 360 Inc.) + (CVE-2016-6304) + [Matt Caswell] + + *) SSL_peek() hang on empty record + + OpenSSL 1.1.0 SSL/TLS will hang during a call to SSL_peek() if the peer + sends an empty record. This could be exploited by a malicious peer in a + Denial Of Service attack. + + This issue was reported to OpenSSL by Alex Gaynor. + (CVE-2016-6305) + [Matt Caswell] + + *) Excessive allocation of memory in tls_get_message_header() and + dtls1_preprocess_fragment() + + A (D)TLS message includes 3 bytes for its length in the header for the + message. This would allow for messages up to 16Mb in length. Messages of + this length are excessive and OpenSSL includes a check to ensure that a + peer is sending reasonably sized messages in order to avoid too much memory + being consumed to service a connection. A flaw in the logic of version + 1.1.0 means that memory for the message is allocated too early, prior to + the excessive message length check. Due to way memory is allocated in + OpenSSL this could mean an attacker could force up to 21Mb to be allocated + to service a connection. This could lead to a Denial of Service through + memory exhaustion. However, the excessive message length check still takes + place, and this would cause the connection to immediately fail. Assuming + that the application calls SSL_free() on the failed conneciton in a timely + manner then the 21Mb of allocated memory will then be immediately freed + again. Therefore the excessive memory allocation will be transitory in + nature. This then means that there is only a security impact if: + + 1) The application does not call SSL_free() in a timely manner in the event + that the connection fails + or + 2) The application is working in a constrained environment where there is + very little free memory + or + 3) The attacker initiates multiple connection attempts such that there are + multiple connections in a state where memory has been allocated for the + connection; SSL_free() has not yet been called; and there is insufficient + memory to service the multiple requests. + + Except in the instance of (1) above any Denial Of Service is likely to be + transitory because as soon as the connection fails the memory is + subsequently freed again in the SSL_free() call. However there is an + increased risk during this period of application crashes due to the lack of + memory - which would then mean a more serious Denial of Service. + + This issue was reported to OpenSSL by Shi Lei (Gear Team, Qihoo 360 Inc.) + (CVE-2016-6307 and CVE-2016-6308) + [Matt Caswell] + *) solaris-x86-cc, i.e. 32-bit configuration with vendor compiler, had to be removed. Primary reason is that vendor assembler can't assemble our modules with -KPIC flag. As result it, assembly @@ -7,7 +7,12 @@ Major changes between OpenSSL 1.1.0 and OpenSSL 1.1.0a [under development] - o + o OCSP Status Request extension unbounded memory growth (CVE-2016-6304) + o SSL_peek() hang on empty record (CVE-2016-6305) + o Excessive allocation of memory in tls_get_message_header() + (CVE-2016-6307) + o Excessive allocation of memory in dtls1_preprocess_fragment() + (CVE-2016-6308) Major changes between OpenSSL 1.0.2h and OpenSSL 1.1.0 [25 Aug 2016] |