diff --git a/openssh-6.9p1-xauth.patch b/openssh-6.9p1-xauth.patch new file mode 100644 index 0000000..b607856 --- /dev/null +++ b/openssh-6.9p1-xauth.patch @@ -0,0 +1,72 @@ +commit 9d47b8d3f50c3a6282896df8274147e3b9a38c56 +Author: Damien Miller +Date: Thu Mar 10 05:03:39 2016 +1100 + + sanitise characters destined for xauth(1) + + reported by github.com/tintinweb + +diff --git a/session.c b/session.c +index 7a02500..87fddfc 100644 +--- a/session.c ++++ b/session.c +@@ -46,6 +46,7 @@ + + #include + ++#include + #include + #include + #include +@@ -274,6 +275,21 @@ do_authenticated(Authctxt *authctxt) + do_cleanup(authctxt); + } + ++/* Check untrusted xauth strings for metacharacters */ ++static int ++xauth_valid_string(const char *s) ++{ ++ size_t i; ++ ++ for (i = 0; s[i] != '\0'; i++) { ++ if (!isalnum((u_char)s[i]) && ++ s[i] != '.' && s[i] != ':' && s[i] != '/' && ++ s[i] != '-' && s[i] != '_') ++ return 0; ++ } ++ return 1; ++} ++ + /* + * Prepares for an interactive session. This is called after the user has + * been successfully authenticated. During this message exchange, pseudo +@@ -347,7 +363,13 @@ do_authenticated1(Authctxt *authctxt) + s->screen = 0; + } + packet_check_eom(); +- success = session_setup_x11fwd(s); ++ if (xauth_valid_string(s->auth_proto) && ++ xauth_valid_string(s->auth_data)) ++ success = session_setup_x11fwd(s); ++ else { ++ success = 0; ++ error("Invalid X11 forwarding data"); ++ } + if (!success) { + free(s->auth_proto); + free(s->auth_data); +@@ -2178,7 +2200,13 @@ session_x11_req(Session *s) + s->screen = packet_get_int(); + packet_check_eom(); + +- success = session_setup_x11fwd(s); ++ if (xauth_valid_string(s->auth_proto) && ++ xauth_valid_string(s->auth_data)) ++ success = session_setup_x11fwd(s); ++ else { ++ success = 0; ++ error("Invalid X11 forwarding data"); ++ } + if (!success) { + free(s->auth_proto); + free(s->auth_data); diff --git a/openssh.spec b/openssh.spec index ec9b9ad..af1b9de 100644 --- a/openssh.spec +++ b/openssh.spec @@ -240,6 +240,8 @@ Patch934: openssh-6.9p1-gssKexAlgorithms.patch # CVE-2016-0777 OpenSSH: Client Information leak due to use of roaming connection feature # Fix an out of-bound read access in the packet handling code Patch935: openssh-6.9p1-security-7.1.patch +# Fix for security issue (openssh-7.2p2): sanitise characters destined for xauth(1) +Patch936: openssh-6.9p1-xauth.patch License: BSD @@ -468,6 +470,7 @@ popd %patch933 -p1 -b .fingerprint %patch934 -p1 -b .gsskexalg %patch935 -p1 -b .security71 +%patch936 -p1 -b .xauth %patch200 -p1 -b .audit %patch700 -p1 -b .fips