| Subject: [PATCH] Fix CVE-2017-16927 |
| |
| sesman: scpv0, accept variable length data fields |
| |
| Upstream-Status: Backport |
| |
| --- |
| sesman/libscp/libscp_v0.c | 32 +++++++++++++++++++++++++------- |
| 1 file changed, 25 insertions(+), 7 deletions(-) |
| |
| diff --git a/sesman/libscp/libscp_v0.c b/sesman/libscp/libscp_v0.c |
| index 5a0c8bf..5693407 100644 |
| --- a/sesman/libscp/libscp_v0.c |
| +++ b/sesman/libscp/libscp_v0.c |
| @@ -161,7 +161,7 @@ scp_v0s_accept(struct SCP_CONNECTION *c, struct SCP_SESSION **s, int skipVchk) |
| struct SCP_SESSION *session = 0; |
| tui16 sz; |
| tui32 code = 0; |
| - char buf[257]; |
| + char *buf = 0; |
| |
| if (!skipVchk) |
| { |
| @@ -226,27 +226,31 @@ scp_v0s_accept(struct SCP_CONNECTION *c, struct SCP_SESSION **s, int skipVchk) |
| |
| /* reading username */ |
| in_uint16_be(c->in_s, sz); |
| - buf[sz] = '\0'; |
| + buf = g_new0(char, sz); |
| in_uint8a(c->in_s, buf, sz); |
| - |
| + buf[sz] = '\0'; |
| if (0 != scp_session_set_username(session, buf)) |
| { |
| scp_session_destroy(session); |
| log_message(LOG_LEVEL_WARNING, "[v0:%d] connection aborted: error setting username", __LINE__); |
| + g_free(buf); |
| return SCP_SERVER_STATE_INTERNAL_ERR; |
| } |
| + g_free(buf); |
| |
| /* reading password */ |
| in_uint16_be(c->in_s, sz); |
| - buf[sz] = '\0'; |
| + buf = g_new0(char, sz); |
| in_uint8a(c->in_s, buf, sz); |
| - |
| + buf[sz] = '\0'; |
| if (0 != scp_session_set_password(session, buf)) |
| { |
| scp_session_destroy(session); |
| log_message(LOG_LEVEL_WARNING, "[v0:%d] connection aborted: error setting password", __LINE__); |
| + g_free(buf); |
| return SCP_SERVER_STATE_INTERNAL_ERR; |
| } |
| + g_free(buf); |
| |
| /* width */ |
| in_uint16_be(c->in_s, sz); |
| @@ -272,9 +276,11 @@ scp_v0s_accept(struct SCP_CONNECTION *c, struct SCP_SESSION **s, int skipVchk) |
| |
| if (sz > 0) |
| { |
| + buf = g_new0(char, sz); |
| in_uint8a(c->in_s, buf, sz); |
| buf[sz] = '\0'; |
| scp_session_set_domain(session, buf); |
| + g_free(buf); |
| } |
| } |
| |
| @@ -285,9 +291,11 @@ scp_v0s_accept(struct SCP_CONNECTION *c, struct SCP_SESSION **s, int skipVchk) |
| |
| if (sz > 0) |
| { |
| + buf = g_new0(char, sz); |
| in_uint8a(c->in_s, buf, sz); |
| buf[sz] = '\0'; |
| scp_session_set_program(session, buf); |
| + g_free(buf); |
| } |
| } |
| |
| @@ -298,9 +306,11 @@ scp_v0s_accept(struct SCP_CONNECTION *c, struct SCP_SESSION **s, int skipVchk) |
| |
| if (sz > 0) |
| { |
| + buf = g_new0(char, sz); |
| in_uint8a(c->in_s, buf, sz); |
| buf[sz] = '\0'; |
| scp_session_set_directory(session, buf); |
| + g_free(buf); |
| } |
| } |
| |
| @@ -311,9 +321,11 @@ scp_v0s_accept(struct SCP_CONNECTION *c, struct SCP_SESSION **s, int skipVchk) |
| |
| if (sz > 0) |
| { |
| + buf = g_new0(char, sz); |
| in_uint8a(c->in_s, buf, sz); |
| buf[sz] = '\0'; |
| scp_session_set_client_ip(session, buf); |
| + g_free(buf); |
| } |
| } |
| } |
| @@ -332,29 +344,35 @@ scp_v0s_accept(struct SCP_CONNECTION *c, struct SCP_SESSION **s, int skipVchk) |
| scp_session_set_type(session, SCP_GW_AUTHENTICATION); |
| /* reading username */ |
| in_uint16_be(c->in_s, sz); |
| - buf[sz] = '\0'; |
| + buf = g_new0(char, sz); |
| in_uint8a(c->in_s, buf, sz); |
| + buf[sz] = '\0'; |
| |
| /* g_writeln("Received user name: %s",buf); */ |
| if (0 != scp_session_set_username(session, buf)) |
| { |
| scp_session_destroy(session); |
| /* until syslog merge log_message(s_log, LOG_LEVEL_WARNING, "[v0:%d] connection aborted: error setting username", __LINE__);*/ |
| + g_free(buf); |
| return SCP_SERVER_STATE_INTERNAL_ERR; |
| } |
| + g_free(buf); |
| |
| /* reading password */ |
| in_uint16_be(c->in_s, sz); |
| - buf[sz] = '\0'; |
| + buf = g_new0(char, sz); |
| in_uint8a(c->in_s, buf, sz); |
| + buf[sz] = '\0'; |
| |
| /* g_writeln("Received password: %s",buf); */ |
| if (0 != scp_session_set_password(session, buf)) |
| { |
| scp_session_destroy(session); |
| /* until syslog merge log_message(s_log, LOG_LEVEL_WARNING, "[v0:%d] connection aborted: error setting password", __LINE__); */ |
| + g_free(buf); |
| return SCP_SERVER_STATE_INTERNAL_ERR; |
| } |
| + g_free(buf); |
| } |
| else |
| { |
| -- |
| 2.7.4 |
| |