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https://gitlab.com/openconnect/ocserv.git
synced 2026-08-09 09:51:49 +08:00
Nikos Mavrogiannopoulos
d79eda6013
ip_route_sanity_check() was a format normalizer, not a validator: any dot-free route (all IPv6, or arbitrary text) returned success unexamined, and a dotted-netmask IPv4 route passed through unchanged. Since route_adddel() substitutes the validated route into route-add-cmd/route-del-cmd and executes it via `/bin/sh -c` as root, a route string carrying shell metacharacters that survived this check was a root command-injection vector. Rewrite the check to fully parse the route as an IPv4 or IPv6 address plus prefix, or the literal keyword "default" (the documented all-traffic-through-VPN shortcut, checked separately by config.c after this function runs), and reject anything left over. Numeric IPv4 prefixes are still normalized to a dotted netmask as before. Adds REQ-MAIN-SEC-008 and tests/route-sanity-check.c, confirmed against real config/test usage (including "route = default") so the stricter validation doesn't regress documented syntax. Signed-off-by: Nikos Mavrogiannopoulos <n.mavrogiannopoulos@gmail.com>
112 lines
3.4 KiB
C
112 lines
3.4 KiB
C
/*
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* Copyright (C) 2026 Nikos Mavrogiannopoulos
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/* REQ-MAIN-SEC-008: ip_route_sanity_check() is the only validation a
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* route string undergoes before it can be substituted into
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* route-add-cmd/route-del-cmd and executed via `/bin/sh -c` as root
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* (src/route-add.c:50). It must reject anything that is not a
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* well-formed IPv4/IPv6 CIDR, not merely normalize IPv4 prefix syntax.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <talloc.h>
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#include "../src/ip-util.h"
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#include "../src/ip-util.c"
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static void expect_reject(const char *route)
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{
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void *pool = talloc_new(NULL);
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char *r = talloc_strdup(pool, route);
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int ret;
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ret = ip_route_sanity_check(pool, &r);
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if (ret >= 0) {
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fprintf(stderr,
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"error: route '%s' should have been REJECTED but was accepted as '%s'\n",
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route, r);
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exit(1);
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}
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talloc_free(pool);
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}
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static void expect_accept(const char *route, const char *expected)
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{
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void *pool = talloc_new(NULL);
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char *r = talloc_strdup(pool, route);
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int ret;
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ret = ip_route_sanity_check(pool, &r);
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if (ret < 0) {
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fprintf(stderr,
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"error: route '%s' should have been ACCEPTED but was rejected\n",
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route);
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exit(1);
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}
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if (strcmp(r, expected) != 0) {
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fprintf(stderr,
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"error: route '%s' normalized to '%s', expected '%s'\n",
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route, r, expected);
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exit(1);
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}
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talloc_free(pool);
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}
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int main(void)
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{
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/* --- malicious routes: MUST be rejected regardless of family --- */
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/* dot-free routes (IPv6, or garbage) used to bypass all validation */
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expect_reject("::/0; touch /tmp/x");
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expect_reject("2001:db8::/32; touch /tmp/x");
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expect_reject("not-a-route-at-all");
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expect_reject("$(touch /tmp/x)");
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expect_reject("`touch /tmp/x`");
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/* dotted-netmask routes used to pass through unexamined */
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expect_reject("1.2.3.4/5.6.7.8; touch /tmp/x");
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expect_reject("10.0.0.0/255.255.255.0; touch /tmp/x");
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expect_reject("10.0.0.0/255.255.255.0 && touch /tmp/x");
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/* out-of-range / malformed prefixes */
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expect_reject("10.0.0.0/33");
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expect_reject("2001:db8::/129");
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expect_reject("10.0.0.0/abc");
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expect_reject("999.999.999.999/24");
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/* --- legitimate routes: MUST still be accepted --- */
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expect_accept("10.0.0.0/24", "10.0.0.0/255.255.255.0");
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expect_accept("10.0.0.0/255.255.255.0", "10.0.0.0/255.255.255.0");
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expect_accept("2001:db8::/32", "2001:db8::/32");
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expect_accept("fd00::/8", "fd00::/8");
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expect_accept("0.0.0.0/0", "0.0.0.0/0.0.0.0");
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expect_accept("::/0", "::/0");
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/* the documented "route = default" keyword (sample.config,
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* config.c:2199-2200) is not an address and MUST be accepted
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* unchanged, exact-match only (not as a prefix/substring) */
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expect_accept("default", "default");
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expect_reject("Default");
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expect_reject("default/24");
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expect_reject("default; touch /tmp/x");
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printf("All route sanity check tests passed.\n");
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return 0;
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}
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