[openssl-users] Is openssl a vector of exploit for Qualys Security Advisory CVE-2015-0235 - GHOST: glibc gethostbyname ?
pl
pl at artisanlogiciel.net
Fri Jan 30 21:18:19 UTC 2015
Hi,
I was wondering if openssl a vector of exploitation of Qualys Security
Advisory CVE-2015-0235 - GHOST: glibc gethostbyname ?
reference and test code here
http://www.openwall.com/lists/oss-security/2015/01/27/9
Here my quick study gethostbyname can be found only in b_sock.c used by
struct hostent *BIO_gethostbyname(const char *name).
so i guess using BIO_gethostbyname is a possible vector of use of this
vulnerability.
i searched for usages of BIO_gethostbyname in openssl code too.
I reviewed BIO_get_host_ip(const char *str, unsigned char *ip) since
even if it can call BIO_gethostbyname t won't do it if it is already
detected as an ip, what is one of the requirements of the vulnerability.
BIO_get_host_ip itself can be called by BIO_get_accept_socket when using
BIO_do_accept(sock) on accept sockets, but since getaddrinfo is defined
( in glibc , could be wrong in some specific cases ? ) and then
EAI_FAMILY, this BIO_get_host_ip won't in fact be called.
So it look like only direct use of BIO_gethostbyname can cause issues
and openssl does not rely on obsolete gethostbyname if it can use
alternate getaddrinfo.
I would be happy to receive any comment on that.
Regards,
Philippe Lhardy
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