| From f7d268864a2660b7239b9a8ff5ad37faeeb751ba Mon Sep 17 00:00:00 2001 |
| From: Jouni Malinen <jouni@codeaurora.org> |
| Date: Wed, 3 Jun 2020 22:41:02 +0300 |
| Subject: [PATCH 2/3] WPS UPnP: Fix event message generation using a long URL |
| path |
| |
| More than about 700 character URL ended up overflowing the wpabuf used |
| for building the event notification and this resulted in the wpabuf |
| buffer overflow checks terminating the hostapd process. Fix this by |
| allocating the buffer to be large enough to contain the full URL path. |
| However, since that around 700 character limit has been the practical |
| limit for more than ten years, start explicitly enforcing that as the |
| limit or the callback URLs since any longer ones had not worked before |
| and there is no need to enable them now either. |
| |
| Upstream-Status: Backport |
| CVE: CVE-2020-12695 patch #2 |
| Signed-off-by: Jouni Malinen <jouni@codeaurora.org> |
| Signed-off-by: Armin Kuster <akuster@mvista.com> |
| |
| --- |
| src/wps/wps_upnp.c | 9 +++++++-- |
| src/wps/wps_upnp_event.c | 3 ++- |
| 2 files changed, 9 insertions(+), 3 deletions(-) |
| |
| diff --git a/src/wps/wps_upnp.c b/src/wps/wps_upnp.c |
| index 7d4b7439940e..ab685d52ecab 100644 |
| --- a/src/wps/wps_upnp.c |
| +++ b/src/wps/wps_upnp.c |
| @@ -328,9 +328,14 @@ static void subscr_addr_add_url(struct subscription *s, const char *url, |
| int rerr; |
| size_t host_len, path_len; |
| |
| - /* url MUST begin with http: */ |
| - if (url_len < 7 || os_strncasecmp(url, "http://", 7)) |
| + /* URL MUST begin with HTTP scheme. In addition, limit the length of |
| + * the URL to 700 characters which is around the limit that was |
| + * implicitly enforced for more than 10 years due to a bug in |
| + * generating the event messages. */ |
| + if (url_len < 7 || os_strncasecmp(url, "http://", 7) || url_len > 700) { |
| + wpa_printf(MSG_DEBUG, "WPS UPnP: Reject an unacceptable URL"); |
| goto fail; |
| + } |
| url += 7; |
| url_len -= 7; |
| |
| diff --git a/src/wps/wps_upnp_event.c b/src/wps/wps_upnp_event.c |
| index d7e6edcc6503..08a23612f338 100644 |
| --- a/src/wps/wps_upnp_event.c |
| +++ b/src/wps/wps_upnp_event.c |
| @@ -147,7 +147,8 @@ static struct wpabuf * event_build_message(struct wps_event_ *e) |
| struct wpabuf *buf; |
| char *b; |
| |
| - buf = wpabuf_alloc(1000 + wpabuf_len(e->data)); |
| + buf = wpabuf_alloc(1000 + os_strlen(e->addr->path) + |
| + wpabuf_len(e->data)); |
| if (buf == NULL) |
| return NULL; |
| wpabuf_printf(buf, "NOTIFY %s HTTP/1.1\r\n", e->addr->path); |
| -- |
| 2.20.1 |