Arch Linux Security Advisory ASA-201503-16 ========================================== Severity: High Date : 2015-03-19 CVE-ID : CVE-2015-1787 CVE-2015-0207 CVE-2015-0208 CVE-2015-0209 CVE-2015-0285 CVE-2015-0286 CVE-2015-0287 CVE-2015-0288 CVE-2015-0289 CVE-2015-0290 CVE-2015-0291 CVE-2015-0293 Package : openssl Type : multiple issues Remote : Yes Link : https://wiki.archlinux.org/index.php/CVE Summary ======= The package openssl before version 1.0.2.a-1 is vulnerable to multiple issues including but not limited to denial of service, unseeded PRNG and memory corruption. Resolution ========== Upgrade to 1.0.2.a-1. # pacman -Syu "openssl>=1.0.2.a-1" The problems have been fixed upstream in version 1.0.2.a. Workaround ========== None. Description =========== - CVE-2015-1787 (denial of service) If client auth is used then a server can segfault in the event of a DHE ciphersuite being selected and a zero length ClientKeyExchange message being sent by the client. This could be exploited in a DoS attack. - CVE-2015-0207 (denial of service) The DTLSv1_listen function is intended to be stateless and processes the initial ClientHello from many peers. It is common for user code to loop over the call to DTLSv1_listen until a valid ClientHello is received with an associated cookie. A defect in the implementation of DTLSv1_listen means that state is preserved in the SSL object from one invocation to the next that can lead to a segmentation fault. Errors processing the initial ClientHello can trigger this scenario. An example of such an error could be that a DTLS1.0 only client is attempting to connect to a DTLS1.2 only server. - CVE-2015-0208 (denial of service) The signature verification routines will crash with a NULL pointer dereference if presented with an ASN.1 signature using the RSA PSS algorithm and invalid parameters. Since these routines are used to verify certificate signature algorithms this can be used to crash any certificate verification operation and exploited in a DoS attack. Any application which performs certificate verification is vulnerable including OpenSSL clients and servers which enable client authentication. - CVE-2015-0209 (denial of service) A malformed EC private key file consumed via the d2i_ECPrivateKey function could cause a use after free condition. This, in turn, could cause a double free in several private key parsing functions (such as d2i_PrivateKey or EVP_PKCS82PKEY) and could lead to a DoS attack or memory corruption for applications that receive EC private keys from untrusted sources. This scenario is considered rare. - CVE-2015-0285 (unseeded PRNG) Under certain conditions an OpenSSL 1.0.2 client can complete a handshake with an unseeded PRNG. The conditions are: - The client is on a platform where the PRNG has not been seeded automatically, and the user has not seeded manually - A protocol specific client method version has been used (i.e. not SSL_client_methodv23) - A ciphersuite is used that does not require additional random data from the PRNG beyond the initial ClientHello client random (e.g. PSK-RC4-SHA). If the handshake succeeds then the client random that has been used will have been generated from a PRNG with insufficient entropy and therefore the output may be predictable. - CVE-2015-0286 (denial of service) The function ASN1_TYPE_cmp will crash with an invalid read if an attempt is made to compare ASN.1 boolean types. Since ASN1_TYPE_cmp is used to check certificate signature algorithm consistency this can be used to crash any certificate verification operation and exploited in a DoS attack. Any application which performs certificate verification is vulnerable including OpenSSL clients and servers which enable client authentication. - CVE-2015-0287 (memory corruption) Reusing a structure in ASN.1 parsing may allow an attacker to cause memory corruption via an invalid write. Such reuse is and has bee strongly discouraged and is believed to be rare. Applications that parse structures containing CHOICE or ANY DEFINED BY components may be affected. Certificate parsing (d2i_X509 and related functions) are however not affected. OpenSSL clients and servers are not affected. - CVE-2015-0288 (denial of service) The function X509_to_X509_REQ will crash with a NULL pointer dereference if the certificate key is invalid. This function is rarely used in practice. - CVE-2015-0289 (denial of service) The PKCS#7 parsing code does not handle missing outer ContentInfo correctly. An attacker can craft malformed ASN.1-encoded PKCS#7 blobs with missing content and trigger a NULL pointer dereference on parsing. Applications that verify PKCS#7 signatures, decrypt PKCS#7 data or otherwise parse PKCS#7 structures from untrusted sources are affected. OpenSSL clients and servers are not affected. - CVE-2015-0290 (denial of service) OpenSSL 1.0.2 introduced the "multiblock" performance improvement. This feature only applies on 64 bit x86 architecture platforms that support AES NI instructions. A defect in the implementation of "multiblock" can cause OpenSSL's internal write buffer to become incorrectly set to NULL when using non-blocking IO. Typically, when the user application is using a socket BIO for writing, this will only result in a failed connection. However if some other BIO is used then it is likely that a segmentation fault will be triggered, thus enabling a potential DoS attack. - CVE-2015-0291 (denial of service) If a client connects to an OpenSSL 1.0.2 server and renegotiates via ClientHello with an invalid signature algorithms extension a NULL pointer dereference will occur. This can be exploited in a DoS attack against the server. - CVE-2015-0293 (denial of service) A malicious client can trigger an OPENSSL_assert (i.e., an abort) in servers that both support SSLv2 and enable export cipher suites by sending a specially crafted SSLv2 CLIENT-MASTER-KEY message. Impact ====== A remote attacker is able to perform denial of service, memory corruption or possibly take advantage of an unseeded PRNG via various vectors. References ========== https://www.openssl.org/news/secadv_20150319.txt https://access.redhat.com/security/cve/CVE-2015-1787 https://access.redhat.com/security/cve/CVE-2015-0207 https://access.redhat.com/security/cve/CVE-2015-0208 https://access.redhat.com/security/cve/CVE-2015-0209 https://access.redhat.com/security/cve/CVE-2015-0285 https://access.redhat.com/security/cve/CVE-2015-0286 https://access.redhat.com/security/cve/CVE-2015-0287 https://access.redhat.com/security/cve/CVE-2015-0288 https://access.redhat.com/security/cve/CVE-2015-0289 https://access.redhat.com/security/cve/CVE-2015-0290 https://access.redhat.com/security/cve/CVE-2015-0291 https://access.redhat.com/security/cve/CVE-2015-0293 https://bugs.archlinux.org/task/44227