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authorPeter Marko <peter.marko@siemens.com>2025-08-10 15:22:18 +0200
committerSteve Sakoman <steve@sakoman.com>2025-08-15 09:06:40 -0700
commitae3cd7bd8a33ca0a87c64fe14e2d27b9df6794e8 (patch)
treeadfce5181cfde70b6d25d6ff1181b42bba96d6e3
parent2dc7ee3894c0918e6718242f7f381a5a39b03fd6 (diff)
downloadpoky-ae3cd7bd8a33ca0a87c64fe14e2d27b9df6794e8.tar.gz
dropbear: patch CVE-2025-47203
Pick patch per Debian security page [1]. [1] https://security-tracker.debian.org/tracker/CVE-2025-47203 (From OE-Core rev: b109c117e68bf44f623124ea1bb2468f3657665c) Signed-off-by: Peter Marko <peter.marko@siemens.com> Signed-off-by: Steve Sakoman <steve@sakoman.com>
Diffstat
-rw-r--r--meta/recipes-core/dropbear/dropbear/CVE-2025-47203.patch373
-rw-r--r--meta/recipes-core/dropbear/dropbear_2024.86.bb1
2 files changed, 374 insertions, 0 deletions
diff --git a/meta/recipes-core/dropbear/dropbear/CVE-2025-47203.patch b/meta/recipes-core/dropbear/dropbear/CVE-2025-47203.patch
new file mode 100644
index 0000000000..9ce0f10588
--- /dev/null
+++ b/meta/recipes-core/dropbear/dropbear/CVE-2025-47203.patch
@@ -0,0 +1,373 @@
1From e5a0ef27c227f7ae69d9a9fec98a056494409b9b Mon Sep 17 00:00:00 2001
2From: Matt Johnston <matt@ucc.asn.au>
3Date: Mon, 5 May 2025 23:14:19 +0800
4Subject: [PATCH] Execute multihop commands directly, no shell
5
6This avoids problems with shell escaping if arguments contain special
7characters.
8
9CVE: CVE-2025-47203
10Upstream-Status: Backport [https://github.com/mkj/dropbear/commit/e5a0ef27c227f7ae69d9a9fec98a056494409b9b]
11Signed-off-by: Peter Marko <peter.marko@siemens.com>
12---
13 src/cli-main.c | 59 +++++++++++++++++---------
14 src/cli-runopts.c | 104 ++++++++++++++++++++++++++++------------------
15 src/dbutil.c | 9 +++-
16 src/dbutil.h | 1 +
17 src/runopts.h | 5 +++
18 5 files changed, 117 insertions(+), 61 deletions(-)
19
20diff --git a/src/cli-main.c b/src/cli-main.c
21index 065fd76..2fafa88 100644
22--- a/src/cli-main.c
23+++ b/src/cli-main.c
24@@ -77,9 +77,8 @@ int main(int argc, char ** argv) {
25 }
26
27 #if DROPBEAR_CLI_PROXYCMD
28- if (cli_opts.proxycmd) {
29+ if (cli_opts.proxycmd || cli_opts.proxyexec) {
30 cli_proxy_cmd(&sock_in, &sock_out, &proxy_cmd_pid);
31- m_free(cli_opts.proxycmd);
32 if (signal(SIGINT, kill_proxy_sighandler) == SIG_ERR ||
33 signal(SIGTERM, kill_proxy_sighandler) == SIG_ERR ||
34 signal(SIGHUP, kill_proxy_sighandler) == SIG_ERR) {
35@@ -101,7 +100,8 @@ int main(int argc, char ** argv) {
36 }
37 #endif /* DBMULTI stuff */
38
39-static void exec_proxy_cmd(const void *user_data_cmd) {
40+#if DROPBEAR_CLI_PROXYCMD
41+static void shell_proxy_cmd(const void *user_data_cmd) {
42 const char *cmd = user_data_cmd;
43 char *usershell;
44
45@@ -110,41 +110,62 @@ static void exec_proxy_cmd(const void *user_data_cmd) {
46 dropbear_exit("Failed to run '%s'\n", cmd);
47 }
48
49-#if DROPBEAR_CLI_PROXYCMD
50+static void exec_proxy_cmd(const void *unused) {
51+ (void)unused;
52+ run_command(cli_opts.proxyexec[0], cli_opts.proxyexec, ses.maxfd);
53+ dropbear_exit("Failed to run '%s'\n", cli_opts.proxyexec[0]);
54+}
55+
56 static void cli_proxy_cmd(int *sock_in, int *sock_out, pid_t *pid_out) {
57- char * ex_cmd = NULL;
58- size_t ex_cmdlen;
59+ char * cmd_arg = NULL;
60+ void (*exec_fn)(const void *user_data) = NULL;
61 int ret;
62
63+ /* exactly one of cli_opts.proxycmd or cli_opts.proxyexec should be set */
64+
65 /* File descriptor "-j &3" */
66- if (*cli_opts.proxycmd == '&') {
67+ if (cli_opts.proxycmd && *cli_opts.proxycmd == '&') {
68 char *p = cli_opts.proxycmd + 1;
69 int sock = strtoul(p, &p, 10);
70 /* must be a single number, and not stdin/stdout/stderr */
71 if (sock > 2 && sock < 1024 && *p == '\0') {
72 *sock_in = sock;
73 *sock_out = sock;
74- return;
75+ goto cleanup;
76 }
77 }
78
79- /* Normal proxycommand */
80+ if (cli_opts.proxycmd) {
81+ /* Normal proxycommand */
82+ size_t shell_cmdlen;
83+ /* So that spawn_command knows which shell to run */
84+ fill_passwd(cli_opts.own_user);
85
86- /* So that spawn_command knows which shell to run */
87- fill_passwd(cli_opts.own_user);
88+ shell_cmdlen = strlen(cli_opts.proxycmd) + 6; /* "exec " + command + '\0' */
89+ cmd_arg = m_malloc(shell_cmdlen);
90+ snprintf(cmd_arg, shell_cmdlen, "exec %s", cli_opts.proxycmd);
91+ exec_fn = shell_proxy_cmd;
92+ } else {
93+ /* No shell */
94+ exec_fn = exec_proxy_cmd;
95+ }
96
97- ex_cmdlen = strlen(cli_opts.proxycmd) + 6; /* "exec " + command + '\0' */
98- ex_cmd = m_malloc(ex_cmdlen);
99- snprintf(ex_cmd, ex_cmdlen, "exec %s", cli_opts.proxycmd);
100-
101- ret = spawn_command(exec_proxy_cmd, ex_cmd,
102- sock_out, sock_in, NULL, pid_out);
103- DEBUG1(("cmd: %s pid=%d", ex_cmd,*pid_out))
104- m_free(ex_cmd);
105+ ret = spawn_command(exec_fn, cmd_arg, sock_out, sock_in, NULL, pid_out);
106 if (ret == DROPBEAR_FAILURE) {
107 dropbear_exit("Failed running proxy command");
108 *sock_in = *sock_out = -1;
109 }
110+
111+cleanup:
112+ m_free(cli_opts.proxycmd);
113+ m_free(cmd_arg);
114+ if (cli_opts.proxyexec) {
115+ char **a = NULL;
116+ for (a = cli_opts.proxyexec; *a; a++) {
117+ m_free_direct(*a);
118+ }
119+ m_free(cli_opts.proxyexec);
120+ }
121 }
122
123 static void kill_proxy_sighandler(int UNUSED(signo)) {
124diff --git a/src/cli-runopts.c b/src/cli-runopts.c
125index b664293..a21b7a2 100644
126--- a/src/cli-runopts.c
127+++ b/src/cli-runopts.c
128@@ -556,62 +556,88 @@ void loadidentityfile(const char* filename, int warnfail) {
129
130 /* Fill out -i, -y, -W options that make sense for all
131 * the intermediate processes */
132-static char* multihop_passthrough_args(void) {
133- char *args = NULL;
134- unsigned int len, total;
135+static char** multihop_args(const char* argv0, const char* prior_hops) {
136+ /* null terminated array */
137+ char **args = NULL;
138+ size_t max_args = 14, pos = 0, len;
139 #if DROPBEAR_CLI_PUBKEY_AUTH
140 m_list_elem *iter;
141 #endif
142- /* Sufficient space for non-string args */
143- len = 100;
144
145- /* String arguments have arbitrary length, so determine space required */
146- if (cli_opts.proxycmd) {
147- len += strlen(cli_opts.proxycmd);
148- }
149 #if DROPBEAR_CLI_PUBKEY_AUTH
150 for (iter = cli_opts.privkeys->first; iter; iter = iter->next)
151 {
152- sign_key * key = (sign_key*)iter->item;
153- len += 4 + strlen(key->filename);
154+ /* "-i file" for each */
155+ max_args += 2;
156 }
157 #endif
158
159- args = m_malloc(len);
160- total = 0;
161+ args = m_malloc(sizeof(char*) * max_args);
162+ pos = 0;
163
164- /* Create new argument string */
165+ args[pos] = m_strdup(argv0);
166+ pos++;
167
168 if (cli_opts.quiet) {
169- total += m_snprintf(args+total, len-total, "-q ");
170+ args[pos] = m_strdup("-q");
171+ pos++;
172 }
173
174 if (cli_opts.no_hostkey_check) {
175- total += m_snprintf(args+total, len-total, "-y -y ");
176+ args[pos] = m_strdup("-y");
177+ pos++;
178+ args[pos] = m_strdup("-y");
179+ pos++;
180 } else if (cli_opts.always_accept_key) {
181- total += m_snprintf(args+total, len-total, "-y ");
182+ args[pos] = m_strdup("-y");
183+ pos++;
184 }
185
186 if (cli_opts.batch_mode) {
187- total += m_snprintf(args+total, len-total, "-o BatchMode=yes ");
188+ args[pos] = m_strdup("-o");
189+ pos++;
190+ args[pos] = m_strdup("BatchMode=yes");
191+ pos++;
192 }
193
194 if (cli_opts.proxycmd) {
195- total += m_snprintf(args+total, len-total, "-J '%s' ", cli_opts.proxycmd);
196+ args[pos] = m_strdup("-J");
197+ pos++;
198+ args[pos] = m_strdup(cli_opts.proxycmd);
199+ pos++;
200 }
201
202 if (opts.recv_window != DEFAULT_RECV_WINDOW) {
203- total += m_snprintf(args+total, len-total, "-W %u ", opts.recv_window);
204+ args[pos] = m_strdup("-W");
205+ pos++;
206+ args[pos] = m_malloc(11);
207+ m_snprintf(args[pos], 11, "%u", opts.recv_window);
208+ pos++;
209 }
210
211 #if DROPBEAR_CLI_PUBKEY_AUTH
212 for (iter = cli_opts.privkeys->first; iter; iter = iter->next)
213 {
214 sign_key * key = (sign_key*)iter->item;
215- total += m_snprintf(args+total, len-total, "-i %s ", key->filename);
216+ args[pos] = m_strdup("-i");
217+ pos++;
218+ args[pos] = m_strdup(key->filename);
219+ pos++;
220 }
221 #endif /* DROPBEAR_CLI_PUBKEY_AUTH */
222
223+ /* last hop */
224+ args[pos] = m_strdup("-B");
225+ pos++;
226+ len = strlen(cli_opts.remotehost) + strlen(cli_opts.remoteport) + 2;
227+ args[pos] = m_malloc(len);
228+ snprintf(args[pos], len, "%s:%s", cli_opts.remotehost, cli_opts.remoteport);
229+ pos++;
230+
231+ /* hostnames of prior hops */
232+ args[pos] = m_strdup(prior_hops);
233+ pos++;
234+
235 return args;
236 }
237
238@@ -626,7 +652,7 @@ static char* multihop_passthrough_args(void) {
239 * etc for as many hosts as we want.
240 *
241 * Note that "-J" arguments aren't actually used, instead
242- * below sets cli_opts.proxycmd directly.
243+ * below sets cli_opts.proxyexec directly.
244 *
245 * Ports for hosts can be specified as host/port.
246 */
247@@ -634,7 +660,7 @@ static void parse_multihop_hostname(const char* orighostarg, const char* argv0)
248 char *userhostarg = NULL;
249 char *hostbuf = NULL;
250 char *last_hop = NULL;
251- char *remainder = NULL;
252+ char *prior_hops = NULL;
253
254 /* both scp and rsync parse a user@host argument
255 * and turn it into "-l user host". This breaks
256@@ -652,6 +678,8 @@ static void parse_multihop_hostname(const char* orighostarg, const char* argv0)
257 }
258 userhostarg = hostbuf;
259
260+ /* Split off any last hostname and use that as remotehost/remoteport.
261+ * That is used for authorized_keys checking etc */
262 last_hop = strrchr(userhostarg, ',');
263 if (last_hop) {
264 if (last_hop == userhostarg) {
265@@ -659,32 +687,28 @@ static void parse_multihop_hostname(const char* orighostarg, const char* argv0)
266 }
267 *last_hop = '\0';
268 last_hop++;
269- remainder = userhostarg;
270+ prior_hops = userhostarg;
271 userhostarg = last_hop;
272 }
273
274+ /* Update cli_opts.remotehost and cli_opts.remoteport */
275 parse_hostname(userhostarg);
276
277- if (last_hop) {
278- /* Set up the proxycmd */
279- unsigned int cmd_len = 0;
280- char *passthrough_args = multihop_passthrough_args();
281- cmd_len = strlen(argv0) + strlen(remainder)
282- + strlen(cli_opts.remotehost) + strlen(cli_opts.remoteport)
283- + strlen(passthrough_args)
284- + 30;
285- /* replace proxycmd. old -J arguments have been copied
286- to passthrough_args */
287- cli_opts.proxycmd = m_realloc(cli_opts.proxycmd, cmd_len);
288- m_snprintf(cli_opts.proxycmd, cmd_len, "%s -B %s:%s %s %s",
289- argv0, cli_opts.remotehost, cli_opts.remoteport,
290- passthrough_args, remainder);
291+ /* Construct any multihop proxy command. Use proxyexec to
292+ * avoid worrying about shell escaping. */
293+ if (prior_hops) {
294+ cli_opts.proxyexec = multihop_args(argv0, prior_hops);
295+ /* Any -J argument has been copied to proxyexec */
296+ if (cli_opts.proxycmd) {
297+ m_free(cli_opts.proxycmd);
298+ }
299+
300 #ifndef DISABLE_ZLIB
301- /* The stream will be incompressible since it's encrypted. */
302+ /* This outer stream will be incompressible since it's encrypted. */
303 opts.compress_mode = DROPBEAR_COMPRESS_OFF;
304 #endif
305- m_free(passthrough_args);
306 }
307+
308 m_free(hostbuf);
309 }
310 #endif /* DROPBEAR_CLI_MULTIHOP */
311diff --git a/src/dbutil.c b/src/dbutil.c
312index 2b44921..a70025e 100644
313--- a/src/dbutil.c
314+++ b/src/dbutil.c
315@@ -371,7 +371,6 @@ int spawn_command(void(*exec_fn)(const void *user_data), const void *exec_data,
316 void run_shell_command(const char* cmd, unsigned int maxfd, char* usershell) {
317 char * argv[4];
318 char * baseshell = NULL;
319- unsigned int i;
320
321 baseshell = basename(usershell);
322
323@@ -393,6 +392,12 @@ void run_shell_command(const char* cmd, unsigned int maxfd, char* usershell) {
324 argv[1] = NULL;
325 }
326
327+ run_command(usershell, argv, maxfd);
328+}
329+
330+void run_command(const char* argv0, char** args, unsigned int maxfd) {
331+ unsigned int i;
332+
333 /* Re-enable SIGPIPE for the executed process */
334 if (signal(SIGPIPE, SIG_DFL) == SIG_ERR) {
335 dropbear_exit("signal() error");
336@@ -404,7 +409,7 @@ void run_shell_command(const char* cmd, unsigned int maxfd, char* usershell) {
337 m_close(i);
338 }
339
340- execv(usershell, argv);
341+ execv(argv0, args);
342 }
343
344 #if DEBUG_TRACE
345diff --git a/src/dbutil.h b/src/dbutil.h
346index 05fc50c..bfbed73 100644
347--- a/src/dbutil.h
348+++ b/src/dbutil.h
349@@ -63,6 +63,7 @@ char * stripcontrol(const char * text);
350 int spawn_command(void(*exec_fn)(const void *user_data), const void *exec_data,
351 int *writefd, int *readfd, int *errfd, pid_t *pid);
352 void run_shell_command(const char* cmd, unsigned int maxfd, char* usershell);
353+void run_command(const char* argv0, char** args, unsigned int maxfd);
354 #if ENABLE_CONNECT_UNIX
355 int connect_unix(const char* addr);
356 #endif
357diff --git a/src/runopts.h b/src/runopts.h
358index c4061a0..f255882 100644
359--- a/src/runopts.h
360+++ b/src/runopts.h
361@@ -197,7 +197,12 @@ typedef struct cli_runopts {
362 unsigned int netcat_port;
363 #endif
364 #if DROPBEAR_CLI_PROXYCMD
365+ /* A proxy command to run via the user's shell */
366 char *proxycmd;
367+#endif
368+#if DROPBEAR_CLI_MULTIHOP
369+ /* Similar to proxycmd, but is arguments for execve(), not shell */
370+ char **proxyexec;
371 #endif
372 const char *bind_arg;
373 char *bind_address;
diff --git a/meta/recipes-core/dropbear/dropbear_2024.86.bb b/meta/recipes-core/dropbear/dropbear_2024.86.bb
index be246a0ccd..10b7cb5c03 100644
--- a/meta/recipes-core/dropbear/dropbear_2024.86.bb
+++ b/meta/recipes-core/dropbear/dropbear_2024.86.bb
@@ -21,6 +21,7 @@ SRC_URI = "http://matt.ucc.asn.au/dropbear/releases/dropbear-${PV}.tar.bz2 \
21 file://dropbear.default \ 21 file://dropbear.default \
22 ${@bb.utils.contains('DISTRO_FEATURES', 'pam', '${PAM_SRC_URI}', '', d)} \ 22 ${@bb.utils.contains('DISTRO_FEATURES', 'pam', '${PAM_SRC_URI}', '', d)} \
23 ${@bb.utils.contains('PACKAGECONFIG', 'disable-weak-ciphers', 'file://dropbear-disable-weak-ciphers.patch', '', d)} \ 23 ${@bb.utils.contains('PACKAGECONFIG', 'disable-weak-ciphers', 'file://dropbear-disable-weak-ciphers.patch', '', d)} \
24 file://CVE-2025-47203.patch \
24 " 25 "
25 26
26SRC_URI[sha256sum] = "e78936dffc395f2e0db099321d6be659190966b99712b55c530dd0a1822e0a5e" 27SRC_URI[sha256sum] = "e78936dffc395f2e0db099321d6be659190966b99712b55c530dd0a1822e0a5e"
generated by cgit v1.2.3-54-g00ecf (git 2.39.0) at 2026-01-10 14:19:47 +0000