--- lib/krb5/recvauth.c.orig 2022-09-15 16:54:19.000000000 -0700 +++ lib/krb5/recvauth.c 2022-11-21 14:37:31.130429000 -0800 @@ -98,7 +98,7 @@ const char *version = KRB5_SENDAUTH_VERSION; char her_version[sizeof(KRB5_SENDAUTH_VERSION)]; char *her_appl_version; - uint32_t len; + uint32_t len, bytes; u_char repl; krb5_data data; krb5_flags ap_options; @@ -166,15 +166,21 @@ krb5_net_write (context, p_fd, &repl, 1); return krb5_enomem(context); } - if (krb5_net_read (context, p_fd, her_appl_version, len) != len - || !(*match_appl_version)(match_data, her_appl_version)) { - repl = 2; - krb5_net_write (context, p_fd, &repl, 1); - krb5_set_error_message(context, KRB5_SENDAUTH_BADAPPLVERS, - N_("wrong sendauth application version (%s)", ""), - her_appl_version); - free (her_appl_version); - return KRB5_SENDAUTH_BADAPPLVERS; + if ((bytes = krb5_net_read (context, p_fd, her_appl_version, len))) { + /* PR/267884: String read must always conatain a terminating NUL */ + if (strnlen(her_appl_version, len) == len) + her_appl_version[len-1] = '\0'; + + if (bytes != len || + !(*match_appl_version)(match_data, her_appl_version)) { + repl = 2; + krb5_net_write (context, p_fd, &repl, 1); + krb5_set_error_message(context, KRB5_SENDAUTH_BADAPPLVERS, + N_("wrong sendauth application version (%s)", ""), + her_appl_version); + free (her_appl_version); + return KRB5_SENDAUTH_BADAPPLVERS; + } } free (her_appl_version);