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authorVijay Anusuri <vanusuri@mvista.com>2024-01-19 08:56:19 +0530
committerArmin Kuster <akuster808@gmail.com>2024-02-07 18:41:41 -0500
commit8ce84b09e5877200e4dfaad6d0f8443fbcb6a954 (patch)
treef2d2722374eb709464922997bdb9943332fe5cde
parentdbb7b798f96ab652628743ceb6c7eaa9b593121d (diff)
downloadmeta-openembedded-8ce84b09e5877200e4dfaad6d0f8443fbcb6a954.tar.gz
libssh: Backport fix for CVE-2023-48795
Upstream-Status: Backport [https://gitlab.com/libssh/libssh-mirror/-/commit/4cef5e965a46e9271aed62631b152e4bd23c1e3c & https://gitlab.com/libssh/libssh-mirror/-/commit/0870c8db28be9eb457ee3d4f9a168959d9507efd & https://gitlab.com/libssh/libssh-mirror/-/commit/5846e57538c750c5ce67df887d09fa99861c79c6] Signed-off-by: Vijay Anusuri <vanusuri@mvista.com> Signed-off-by: Armin Kuster <akuster808@gmail.com>
Diffstat
-rw-r--r--meta-oe/recipes-support/libssh/libssh/CVE-2023-48795-1.patch385
-rw-r--r--meta-oe/recipes-support/libssh/libssh/CVE-2023-48795-2.patch126
-rw-r--r--meta-oe/recipes-support/libssh/libssh/CVE-2023-48795-3.patch47
-rw-r--r--meta-oe/recipes-support/libssh/libssh_0.8.9.bb3
4 files changed, 561 insertions, 0 deletions
diff --git a/meta-oe/recipes-support/libssh/libssh/CVE-2023-48795-1.patch b/meta-oe/recipes-support/libssh/libssh/CVE-2023-48795-1.patch
new file mode 100644
index 0000000000..413e5b3d11
--- /dev/null
+++ b/meta-oe/recipes-support/libssh/libssh/CVE-2023-48795-1.patch
@@ -0,0 +1,385 @@
1From 4cef5e965a46e9271aed62631b152e4bd23c1e3c Mon Sep 17 00:00:00 2001
2From: Aris Adamantiadis <aris@0xbadc0de.be>
3Date: Tue, 12 Dec 2023 23:09:57 +0100
4Subject: [PATCH] CVE-2023-48795: client side mitigation
5
6Signed-off-by: Aris Adamantiadis <aris@0xbadc0de.be>
7Signed-off-by: Jakub Jelen <jjelen@redhat.com>
8Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
9
10Upstream-Status: Backport [https://gitlab.com/libssh/libssh-mirror/-/commit/4cef5e965a46e9271aed62631b152e4bd23c1e3c]
11CVE: CVE-2023-48795
12Signed-off-by: Vijay Anusuri <vanusuri@mvista.com>
13---
14 include/libssh/packet.h | 1 +
15 include/libssh/session.h | 6 +++++
16 src/curve25519.c | 18 +++----------
17 src/dh.c | 6 +----
18 src/ecdh.c | 7 +----
19 src/ecdh_crypto.c | 10 ++-----
20 src/ecdh_gcrypt.c | 10 +++----
21 src/ecdh_mbedcrypto.c | 11 +++-----
22 src/kex.c | 34 ++++++++++++++++++++----
23 src/packet.c | 56 +++++++++++++++++++++++++++++++++++++++-
24 src/packet_cb.c | 12 +++++++++
25 11 files changed, 118 insertions(+), 53 deletions(-)
26
27diff --git a/include/libssh/packet.h b/include/libssh/packet.h
28index fbe09700..8800e16b 100644
29--- a/include/libssh/packet.h
30+++ b/include/libssh/packet.h
31@@ -63,6 +63,7 @@ SSH_PACKET_CALLBACK(ssh_packet_ext_info);
32 SSH_PACKET_CALLBACK(ssh_packet_kexdh_init);
33 #endif
34
35+int ssh_packet_send_newkeys(ssh_session session);
36 int ssh_packet_send_unimplemented(ssh_session session, uint32_t seqnum);
37 int ssh_packet_parse_type(ssh_session session);
38 //int packet_flush(ssh_session session, int enforce_blocking);
39diff --git a/include/libssh/session.h b/include/libssh/session.h
40index 23633cc2..b8810f54 100644
41--- a/include/libssh/session.h
42+++ b/include/libssh/session.h
43@@ -69,6 +69,12 @@ enum ssh_pending_call_e {
44 /* Client successfully authenticated */
45 #define SSH_SESSION_FLAG_AUTHENTICATED 2
46
47+/* The current SSH2 session implements the "strict KEX" feature and should behave
48+ * differently on SSH2_MSG_NEWKEYS. */
49+#define SSH_SESSION_FLAG_KEX_STRICT 0x0010
50+/* Unexpected packets have been sent while the session was still unencrypted */
51+#define SSH_SESSION_FLAG_KEX_TAINTED 0x0020
52+
53 /* codes to use with ssh_handle_packets*() */
54 /* Infinite timeout */
55 #define SSH_TIMEOUT_INFINITE -1
56diff --git a/src/curve25519.c b/src/curve25519.c
57index 167209f4..6eda5feb 100644
58--- a/src/curve25519.c
59+++ b/src/curve25519.c
60@@ -166,12 +166,7 @@ int ssh_client_curve25519_reply(ssh_session session, ssh_buffer packet){
61 }
62
63 /* Send the MSG_NEWKEYS */
64- if (ssh_buffer_add_u8(session->out_buffer, SSH2_MSG_NEWKEYS) < 0) {
65- goto error;
66- }
67-
68- rc=ssh_packet_send(session);
69- SSH_LOG(SSH_LOG_PROTOCOL, "SSH_MSG_NEWKEYS sent");
70+ rc = ssh_packet_send_newkeys(session);
71 return rc;
72 error:
73 return SSH_ERROR;
74@@ -297,15 +292,10 @@ int ssh_server_curve25519_init(ssh_session session, ssh_buffer packet){
75 return SSH_ERROR;
76 }
77
78- /* Send the MSG_NEWKEYS */
79- rc = ssh_buffer_add_u8(session->out_buffer, SSH2_MSG_NEWKEYS);
80- if (rc < 0) {
81- goto error;
82- }
83-
84 session->dh_handshake_state = DH_STATE_NEWKEYS_SENT;
85- rc = ssh_packet_send(session);
86- SSH_LOG(SSH_LOG_PROTOCOL, "SSH_MSG_NEWKEYS sent");
87+
88+ /* Send the MSG_NEWKEYS */
89+ rc = ssh_packet_send_newkeys(session);
90
91 return rc;
92 error:
93diff --git a/src/dh.c b/src/dh.c
94index cc12fd46..33883f2d 100644
95--- a/src/dh.c
96+++ b/src/dh.c
97@@ -735,11 +735,7 @@ int ssh_client_dh_reply(ssh_session session, ssh_buffer packet){
98 }
99
100 /* Send the MSG_NEWKEYS */
101- if (ssh_buffer_add_u8(session->out_buffer, SSH2_MSG_NEWKEYS) < 0) {
102- goto error;
103- }
104-
105- rc=ssh_packet_send(session);
106+ rc = ssh_packet_send_newkeys(session);
107 SSH_LOG(SSH_LOG_PROTOCOL, "SSH_MSG_NEWKEYS sent");
108 return rc;
109 error:
110diff --git a/src/ecdh.c b/src/ecdh.c
111index f7fcaf13..1fef7ec9 100644
112--- a/src/ecdh.c
113+++ b/src/ecdh.c
114@@ -72,12 +72,7 @@ int ssh_client_ecdh_reply(ssh_session session, ssh_buffer packet){
115 }
116
117 /* Send the MSG_NEWKEYS */
118- if (ssh_buffer_add_u8(session->out_buffer, SSH2_MSG_NEWKEYS) < 0) {
119- goto error;
120- }
121-
122- rc=ssh_packet_send(session);
123- SSH_LOG(SSH_LOG_PROTOCOL, "SSH_MSG_NEWKEYS sent");
124+ rc = ssh_packet_send_newkeys(session);
125 return rc;
126 error:
127 return SSH_ERROR;
128diff --git a/src/ecdh_crypto.c b/src/ecdh_crypto.c
129index 24f21c03..7e5f0cc7 100644
130--- a/src/ecdh_crypto.c
131+++ b/src/ecdh_crypto.c
132@@ -318,15 +318,9 @@ int ssh_server_ecdh_init(ssh_session session, ssh_buffer packet){
133 return SSH_ERROR;
134 }
135
136- /* Send the MSG_NEWKEYS */
137- rc = ssh_buffer_add_u8(session->out_buffer, SSH2_MSG_NEWKEYS);
138- if (rc < 0) {
139- return SSH_ERROR;;
140- }
141-
142 session->dh_handshake_state = DH_STATE_NEWKEYS_SENT;
143- rc = ssh_packet_send(session);
144- SSH_LOG(SSH_LOG_PROTOCOL, "SSH_MSG_NEWKEYS sent");
145+ /* Send the MSG_NEWKEYS */
146+ rc = ssh_packet_send_newkeys(session);
147
148 return rc;
149 }
150diff --git a/src/ecdh_gcrypt.c b/src/ecdh_gcrypt.c
151index e43cacea..c1db7f5d 100644
152--- a/src/ecdh_gcrypt.c
153+++ b/src/ecdh_gcrypt.c
154@@ -362,17 +362,13 @@ int ssh_server_ecdh_init(ssh_session session, ssh_buffer packet) {
155 goto out;
156 }
157
158-
159+ session->dh_handshake_state = DH_STATE_NEWKEYS_SENT;
160 /* Send the MSG_NEWKEYS */
161- rc = ssh_buffer_add_u8(session->out_buffer, SSH2_MSG_NEWKEYS);
162- if (rc != SSH_OK) {
163+ rc = ssh_packet_send_newkeys(session);
164+ if (rc == SSH_ERROR) {
165 goto out;
166 }
167
168- session->dh_handshake_state = DH_STATE_NEWKEYS_SENT;
169- rc = ssh_packet_send(session);
170- SSH_LOG(SSH_LOG_PROTOCOL, "SSH_MSG_NEWKEYS sent");
171-
172 out:
173 gcry_sexp_release(param);
174 gcry_sexp_release(key);
175diff --git a/src/ecdh_mbedcrypto.c b/src/ecdh_mbedcrypto.c
176index fa350028..24924508 100644
177--- a/src/ecdh_mbedcrypto.c
178+++ b/src/ecdh_mbedcrypto.c
179@@ -293,16 +293,13 @@ int ssh_server_ecdh_init(ssh_session session, ssh_buffer packet)
180 goto out;
181 }
182
183- rc = ssh_buffer_add_u8(session->out_buffer, SSH2_MSG_NEWKEYS);
184- if (rc < 0) {
185- rc = SSH_ERROR;
186+ session->dh_handshake_state = DH_STATE_NEWKEYS_SENT;
187+ /* Send the MSG_NEWKEYS */
188+ rc = ssh_packet_send_newkeys(session);
189+ if (rc == SSH_ERROR) {
190 goto out;
191 }
192
193- session->dh_handshake_state = DH_STATE_NEWKEYS_SENT;
194- rc = ssh_packet_send(session);
195- SSH_LOG(SSH_LOG_PROTOCOL, "SSH_MSG_NEWKEYS sent");
196-
197 out:
198 mbedtls_ecp_group_free(&grp);
199 return rc;
200diff --git a/src/kex.c b/src/kex.c
201index 82686e4b..7f1bb324 100644
202--- a/src/kex.c
203+++ b/src/kex.c
204@@ -105,6 +105,9 @@
205
206 /* RFC 8308 */
207 #define KEX_EXTENSION_CLIENT "ext-info-c"
208+/* Strict kex mitigation against CVE-2023-48795 */
209+#define KEX_STRICT_CLIENT "kex-strict-c-v00@openssh.com"
210+#define KEX_STRICT_SERVER "kex-strict-s-v00@openssh.com"
211
212 /* NOTE: This is a fixed API and the index is defined by ssh_kex_types_e */
213 static const char *default_methods[] = {
214@@ -521,6 +524,27 @@ SSH_PACKET_CALLBACK(ssh_packet_kexinit){
215 goto error;
216 }
217
218+ /*
219+ * handle the "strict KEX" feature. If supported by peer, then set up the
220+ * flag and verify packet sequence numbers.
221+ */
222+ if (server_kex) {
223+ ok = ssh_match_group(session->next_crypto->client_kex.methods[SSH_KEX],
224+ KEX_STRICT_CLIENT);
225+ if (ok) {
226+ SSH_LOG(SSH_LOG_DEBUG, "Client supports strict kex, enabling.");
227+ session->flags |= SSH_SESSION_FLAG_KEX_STRICT;
228+ }
229+ } else {
230+ /* client kex */
231+ ok = ssh_match_group(session->next_crypto->server_kex.methods[SSH_KEX],
232+ KEX_STRICT_SERVER);
233+ if (ok) {
234+ SSH_LOG(SSH_LOG_DEBUG, "Server supports strict kex, enabling.");
235+ session->flags |= SSH_SESSION_FLAG_KEX_STRICT;
236+ }
237+ }
238+
239 /*
240 * If client sent a ext-info-c message in the kex list, it supports
241 * RFC 8308 extension negotiation.
242@@ -778,21 +802,21 @@ int ssh_set_client_kex(ssh_session session)
243 return SSH_OK;
244 }
245
246- /* Here we append ext-info-c to the list of kex algorithms */
247+ /* Here we append ext-info-c and kex-strict-c-v00@openssh.com to the list of kex algorithms */
248 kex = client->methods[SSH_KEX];
249 len = strlen(kex);
250- if (len + strlen(KEX_EXTENSION_CLIENT) + 2 < len) {
251+ /* Comma, comma, nul byte */
252+ kex_len = len + 1 + strlen(KEX_EXTENSION_CLIENT) + 1 + strlen(KEX_STRICT_CLIENT ) + 1;
253+ if (kex_len >= MAX_PACKET_LEN) {
254 /* Overflow */
255 return SSH_ERROR;
256 }
257- kex_len = len + strlen(KEX_EXTENSION_CLIENT) + 2; /* comma, NULL */
258 kex_tmp = realloc(kex, kex_len);
259 if (kex_tmp == NULL) {
260- free(kex);
261 ssh_set_error_oom(session);
262 return SSH_ERROR;
263 }
264- snprintf(kex_tmp + len, kex_len - len, ",%s", KEX_EXTENSION_CLIENT);
265+ snprintf(kex_tmp + len, kex_len - len, ",%s,%s", KEX_EXTENSION_CLIENT, KEX_STRICT_CLIENT);
266 client->methods[SSH_KEX] = kex_tmp;
267
268 return SSH_OK;
269diff --git a/src/packet.c b/src/packet.c
270index 61a44237..8025a7ff 100644
271--- a/src/packet.c
272+++ b/src/packet.c
273@@ -1126,6 +1126,19 @@ int ssh_packet_socket_callback(const void *data, size_t receivedlen, void *user)
274 }
275 #endif /* WITH_ZLIB */
276 payloadsize = ssh_buffer_get_len(session->in_buffer);
277+ if (session->recv_seq == UINT32_MAX) {
278+ /* Overflowing sequence numbers is always fishy */
279+ if (session->current_crypto == NULL) {
280+ /* don't allow sequence number overflow when unencrypted */
281+ ssh_set_error(session,
282+ SSH_FATAL,
283+ "Incoming sequence number overflow");
284+ goto error;
285+ } else {
286+ SSH_LOG(SSH_LOG_WARNING,
287+ "Incoming sequence number overflow");
288+ }
289+ }
290 session->recv_seq++;
291 if (session->raw_counter != NULL) {
292 session->raw_counter->in_bytes += payloadsize;
293@@ -1141,7 +1154,19 @@ int ssh_packet_socket_callback(const void *data, size_t receivedlen, void *user)
294 SSH_LOG(SSH_LOG_PACKET,
295 "packet: read type %hhd [len=%d,padding=%hhd,comp=%d,payload=%d]",
296 session->in_packet.type, packet_len, padding, compsize, payloadsize);
297-
298+ if (session->current_crypto == NULL) {
299+ /* In strict kex, only a few packets are allowed. Taint the session
300+ * if we received packets that are normally allowed but to be
301+ * refused if we are in strict kex when KEX is over.
302+ */
303+ uint8_t type = session->in_packet.type;
304+
305+ if (type != SSH2_MSG_KEXINIT && type != SSH2_MSG_NEWKEYS &&
306+ (type < SSH2_MSG_KEXDH_INIT ||
307+ type > SSH2_MSG_KEX_DH_GEX_REQUEST)) {
308+ session->flags |= SSH_SESSION_FLAG_KEX_TAINTED;
309+ }
310+ }
311 /* Check if the packet is expected */
312 filter_result = ssh_packet_incoming_filter(session);
313
314@@ -1153,6 +1178,9 @@ int ssh_packet_socket_callback(const void *data, size_t receivedlen, void *user)
315 case SSH_PACKET_DENIED:
316 goto error;
317 case SSH_PACKET_UNKNOWN:
318+ if (session->current_crypto == NULL) {
319+ session->flags |= SSH_SESSION_FLAG_KEX_TAINTED;
320+ }
321 ssh_packet_send_unimplemented(session, session->recv_seq - 1);
322 break;
323 }
324@@ -1276,9 +1304,35 @@ void ssh_packet_process(ssh_session session, uint8_t type){
325 if(r==SSH_PACKET_NOT_USED){
326 SSH_LOG(SSH_LOG_RARE,"Couldn't do anything with packet type %d",type);
327 ssh_packet_send_unimplemented(session, session->recv_seq-1);
328+ if (session->current_crypto == NULL) {
329+ session->flags |= SSH_SESSION_FLAG_KEX_TAINTED;
330+ }
331 }
332 }
333
334+/** @internal
335+ * @brief sends a SSH_MSG_NEWKEYS when enabling the new negotiated ciphers
336+ * @param session the SSH session
337+ * @return SSH_ERROR on error, else SSH_OK
338+ */
339+int ssh_packet_send_newkeys(ssh_session session)
340+{
341+ int rc;
342+
343+ /* Send the MSG_NEWKEYS */
344+ rc = ssh_buffer_add_u8(session->out_buffer, SSH2_MSG_NEWKEYS);
345+ if (rc < 0) {
346+ return rc;
347+ }
348+
349+ rc = ssh_packet_send(session);
350+ if (rc == SSH_ERROR) {
351+ return rc;
352+ }
353+ SSH_LOG(SSH_LOG_DEBUG, "SSH_MSG_NEWKEYS sent");
354+ return rc;
355+}
356+
357 /** @internal
358 * @brief sends a SSH_MSG_UNIMPLEMENTED answer to an unhandled packet
359 * @param session the SSH session
360diff --git a/src/packet_cb.c b/src/packet_cb.c
361index 6aa64766..de03fb07 100644
362--- a/src/packet_cb.c
363+++ b/src/packet_cb.c
364@@ -154,6 +154,18 @@ SSH_PACKET_CALLBACK(ssh_packet_newkeys){
365 goto error;
366 }
367
368+ if (session->flags & SSH_SESSION_FLAG_KEX_STRICT) {
369+ /* reset packet sequence number when running in strict kex mode */
370+ session->recv_seq = 0;
371+ /* Check that we aren't tainted */
372+ if (session->flags & SSH_SESSION_FLAG_KEX_TAINTED) {
373+ ssh_set_error(session,
374+ SSH_FATAL,
375+ "Received unexpected packets in strict KEX mode.");
376+ goto error;
377+ }
378+}
379+
380 if(session->server){
381 /* server things are done in server.c */
382 session->dh_handshake_state=DH_STATE_FINISHED;
383--
3842.25.1
385
diff --git a/meta-oe/recipes-support/libssh/libssh/CVE-2023-48795-2.patch b/meta-oe/recipes-support/libssh/libssh/CVE-2023-48795-2.patch
new file mode 100644
index 0000000000..fe3300503f
--- /dev/null
+++ b/meta-oe/recipes-support/libssh/libssh/CVE-2023-48795-2.patch
@@ -0,0 +1,126 @@
1From 0870c8db28be9eb457ee3d4f9a168959d9507efd Mon Sep 17 00:00:00 2001
2From: Aris Adamantiadis <aris@0xbadc0de.be>
3Date: Tue, 12 Dec 2023 23:30:26 +0100
4Subject: [PATCH] CVE-2023-48795: Server side mitigations
5
6Signed-off-by: Aris Adamantiadis <aris@0xbadc0de.be>
7Signed-off-by: Jakub Jelen <jjelen@redhat.com>
8Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
9
10Upstream-Status: Backport [https://gitlab.com/libssh/libssh-mirror/-/commit/0870c8db28be9eb457ee3d4f9a168959d9507efd]
11CVE: CVE-2023-48795
12Signed-off-by: Vijay Anusuri <vanusuri@mvista.com>
13---
14 include/libssh/kex.h | 1 +
15 src/kex.c | 46 ++++++++++++++++++++++++++++++++++----------
16 src/server.c | 8 +++++++-
17 3 files changed, 44 insertions(+), 11 deletions(-)
18
19diff --git a/include/libssh/kex.h b/include/libssh/kex.h
20index a626d105..2b1a74d5 100644
21--- a/include/libssh/kex.h
22+++ b/include/libssh/kex.h
23@@ -36,6 +36,7 @@ SSH_PACKET_CALLBACK(ssh_packet_kexinit);
24 int ssh_send_kex(ssh_session session, int server_kex);
25 void ssh_list_kex(struct ssh_kex_struct *kex);
26 int ssh_set_client_kex(ssh_session session);
27+int ssh_kex_append_extensions(ssh_session session, struct ssh_kex_struct *pkex);
28 int ssh_kex_select_methods(ssh_session session);
29 int ssh_verify_existing_algo(enum ssh_kex_types_e algo, const char *name);
30 char *ssh_keep_known_algos(enum ssh_kex_types_e algo, const char *list);
31diff --git a/src/kex.c b/src/kex.c
32index 2ed90235..b03e6484 100644
33--- a/src/kex.c
34+++ b/src/kex.c
35@@ -766,11 +766,8 @@ int ssh_set_client_kex(ssh_session session)
36 {
37 struct ssh_kex_struct *client= &session->next_crypto->client_kex;
38 const char *wanted;
39- char *kex = NULL;
40- char *kex_tmp = NULL;
41 int ok;
42 int i;
43- size_t kex_len, len;
44
45 ok = ssh_get_random(client->cookie, 16, 0);
46 if (!ok) {
47@@ -802,11 +799,33 @@ int ssh_set_client_kex(ssh_session session)
48 return SSH_OK;
49 }
50
51- /* Here we append ext-info-c and kex-strict-c-v00@openssh.com to the list of kex algorithms */
52- kex = client->methods[SSH_KEX];
53+ ok = ssh_kex_append_extensions(session, client);
54+ if (ok != SSH_OK){
55+ return ok;
56+ }
57+
58+ return SSH_OK;
59+}
60+
61+int ssh_kex_append_extensions(ssh_session session, struct ssh_kex_struct *pkex)
62+{
63+ char *kex = NULL;
64+ char *kex_tmp = NULL;
65+ size_t kex_len, len;
66+
67+ /* Here we append ext-info-c and kex-strict-c-v00@openssh.com for client
68+ * and kex-strict-s-v00@openssh.com for server to the list of kex algorithms
69+ */
70+ kex = pkex->methods[SSH_KEX];
71 len = strlen(kex);
72- /* Comma, comma, nul byte */
73- kex_len = len + 1 + strlen(KEX_EXTENSION_CLIENT) + 1 + strlen(KEX_STRICT_CLIENT ) + 1;
74+ if (session->server) {
75+ /* Comma, nul byte */
76+ kex_len = len + 1 + strlen(KEX_STRICT_SERVER) + 1;
77+ } else {
78+ /* Comma, comma, nul byte */
79+ kex_len = len + 1 + strlen(KEX_EXTENSION_CLIENT) + 1 +
80+ strlen(KEX_STRICT_CLIENT) + 1;
81+ }
82 if (kex_len >= MAX_PACKET_LEN) {
83 /* Overflow */
84 return SSH_ERROR;
85@@ -816,9 +835,16 @@ int ssh_set_client_kex(ssh_session session)
86 ssh_set_error_oom(session);
87 return SSH_ERROR;
88 }
89- snprintf(kex_tmp + len, kex_len - len, ",%s,%s", KEX_EXTENSION_CLIENT, KEX_STRICT_CLIENT);
90- client->methods[SSH_KEX] = kex_tmp;
91-
92+ if (session->server){
93+ snprintf(kex_tmp + len, kex_len - len, ",%s", KEX_STRICT_SERVER);
94+ } else {
95+ snprintf(kex_tmp + len,
96+ kex_len - len,
97+ ",%s,%s",
98+ KEX_EXTENSION_CLIENT,
99+ KEX_STRICT_CLIENT);
100+ }
101+ pkex->methods[SSH_KEX] = kex_tmp;
102 return SSH_OK;
103 }
104
105diff --git a/src/server.c b/src/server.c
106index bc98da4f..f3d24a7b 100644
107--- a/src/server.c
108+++ b/src/server.c
109@@ -158,7 +158,13 @@ static int server_set_kex(ssh_session session) {
110 }
111 }
112
113- return 0;
114+ /* Do not append the extensions during rekey */
115+ if (session->flags & SSH_SESSION_FLAG_AUTHENTICATED) {
116+ return SSH_OK;
117+ }
118+
119+ rc = ssh_kex_append_extensions(session, server);
120+ return rc;
121 }
122
123 int ssh_server_init_kex(ssh_session session) {
124--
1252.25.1
126
diff --git a/meta-oe/recipes-support/libssh/libssh/CVE-2023-48795-3.patch b/meta-oe/recipes-support/libssh/libssh/CVE-2023-48795-3.patch
new file mode 100644
index 0000000000..1635a4c2dc
--- /dev/null
+++ b/meta-oe/recipes-support/libssh/libssh/CVE-2023-48795-3.patch
@@ -0,0 +1,47 @@
1From 5846e57538c750c5ce67df887d09fa99861c79c6 Mon Sep 17 00:00:00 2001
2From: Jakub Jelen <jjelen@redhat.com>
3Date: Thu, 14 Dec 2023 12:22:01 +0100
4Subject: [PATCH] CVE-2023-48795: Strip extensions from both kex lists for
5 matching
6
7Signed-off-by: Jakub Jelen <jjelen@redhat.com>
8Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
9
10Upstream-Status: Backport [https://gitlab.com/libssh/libssh-mirror/-/commit/5846e57538c750c5ce67df887d09fa99861c79c6]
11CVE: CVE-2023-48795
12Signed-off-by: Vijay Anusuri <vanusuri@mvista.com>
13---
14 src/kex.c | 16 ++++++++++++----
15 1 file changed, 12 insertions(+), 4 deletions(-)
16
17diff --git a/src/kex.c b/src/kex.c
18index b03e6484..c100d908 100644
19--- a/src/kex.c
20+++ b/src/kex.c
21@@ -857,11 +857,19 @@ int ssh_kex_select_methods (ssh_session session){
22 char *ext_start = NULL;
23 int i;
24
25- /* Here we should drop the ext-info-c from the list so we avoid matching.
26+ /* Here we should drop the extensions from the list so we avoid matching.
27 * it. We added it to the end, so we can just truncate the string here */
28- ext_start = strstr(client->methods[SSH_KEX], ","KEX_EXTENSION_CLIENT);
29- if (ext_start != NULL) {
30- ext_start[0] = '\0';
31+ if (session->client) {
32+ ext_start = strstr(client->methods[SSH_KEX], "," KEX_EXTENSION_CLIENT);
33+ if (ext_start != NULL) {
34+ ext_start[0] = '\0';
35+ }
36+ }
37+ if (session->server) {
38+ ext_start = strstr(server->methods[SSH_KEX], "," KEX_STRICT_SERVER);
39+ if (ext_start != NULL) {
40+ ext_start[0] = '\0';
41+ }
42 }
43
44 for (i = 0; i < KEX_METHODS_SIZE; i++) {
45--
462.25.1
47
diff --git a/meta-oe/recipes-support/libssh/libssh_0.8.9.bb b/meta-oe/recipes-support/libssh/libssh_0.8.9.bb
index 061f13912f..530dda1f4a 100644
--- a/meta-oe/recipes-support/libssh/libssh_0.8.9.bb
+++ b/meta-oe/recipes-support/libssh/libssh_0.8.9.bb
@@ -8,6 +8,9 @@ DEPENDS = "zlib openssl"
8 8
9SRC_URI = "git://git.libssh.org/projects/libssh.git;protocol=https;branch=stable-0.8 \ 9SRC_URI = "git://git.libssh.org/projects/libssh.git;protocol=https;branch=stable-0.8 \
10 file://CVE-2020-16135.patch \ 10 file://CVE-2020-16135.patch \
11 file://CVE-2023-48795-1.patch \
12 file://CVE-2023-48795-2.patch \
13 file://CVE-2023-48795-3.patch \
11 " 14 "
12SRCREV = "04685a74df9ce1db1bc116a83a0da78b4f4fa1f8" 15SRCREV = "04685a74df9ce1db1bc116a83a0da78b4f4fa1f8"
13 16
generated by cgit v1.2.3-54-g00ecf (git 2.39.0) at 2026-05-08 18:13:18 +0000