Bug 4957: Multiple XSS issues in cachemgr.cgi (squid-cache#429)

The cachemgr.cgi web module of the squid proxy is vulnerable to XSS issue. The vulnerable parameters "user_name" and "auth" have insufficient sanitization in place.
squidadm · Jul 9, 2019 · c09cefd · c09cefd
1 parent 210d946
commit c09cefd
Showing 1 changed file with 8 additions and 6 deletions.
diff --git a/tools/cachemgr.cc b/tools/cachemgr.cc
@@ -354,7 +354,7 @@ auth_html(const char *host, int port, const char *user_name)
 
     printf("<TR><TH ALIGN=\"left\">Manager name:</TH><TD><INPUT NAME=\"user_name\" ");
 
-    printf("size=\"30\" VALUE=\"%s\"></TD></TR>\n", user_name);
+    printf("size=\"30\" VALUE=\"%s\"></TD></TR>\n", rfc1738_escape(user_name));
 
     printf("<TR><TH ALIGN=\"left\">Password:</TH><TD><INPUT TYPE=\"password\" NAME=\"passwd\" ");
 
@@ -418,7 +418,7 @@ menu_url(cachemgr_request * req, const char *action)
              script_name,
              req->hostname,
              req->port,
-             safe_str(req->user_name),
+             rfc1738_escape(safe_str(req->user_name)),
              action,
              safe_str(req->pub_auth));
     return url;
@@ -1073,8 +1073,8 @@ make_pub_auth(cachemgr_request * req)
     const int bufLen = snprintf(buf, sizeof(buf), "%s|%d|%s|%s",
                                 req->hostname,
                                 (int) now,
-                                req->user_name ? req->user_name : "",
-                                req->passwd);
+                                rfc1738_escape(safe_str(req->user_name)),
+                                rfc1738_escape(req->passwd));
     debug("cmgr: pre-encoded for pub: %s\n", buf);
 
     const int encodedLen = base64_encode_len(bufLen);
@@ -1089,8 +1089,6 @@ decode_pub_auth(cachemgr_request * req)
     char *buf;
     const char *host_name;
     const char *time_str;
-    const char *user_name;
-    const char *passwd;
 
     debug("cmgr: decoding pub: '%s'\n", safe_str(req->pub_auth));
     safe_free(req->passwd);
@@ -1119,17 +1117,21 @@ decode_pub_auth(cachemgr_request * req)
 
     debug("cmgr: decoded time: '%s' (now: %d)\n", time_str, (int) now);
 
+    char *user_name;
     if ((user_name = strtok(NULL, "|")) == NULL) {
         xfree(buf);
         return;
     }
+    rfc1738_unescape(user_name);
 
     debug("cmgr: decoded uname: '%s'\n", user_name);
 
+    char *passwd;
     if ((passwd = strtok(NULL, "|")) == NULL) {
         xfree(buf);
         return;
     }
+    rfc1738_unescape(passwd);
 
     debug("cmgr: decoded passwd: '%s'\n", passwd);