NULL pointer crash in websSafeUrl()

Description:

Passing a NULL pointer into the websSafeUrl() function (as would happen when the server is processing an invalid URL) crashes the server.

Fix:

Code modified to check for NULL pointer before performing any string operations.

bopen() failure mode

Description:

New failure behavior for bopen() (see balloc.c)

Fix:

Changed failure behavior of the bopen() function (suggested by Simon Byholm). If the malloc() request fails, we reset the bopenCount variable, and thus allow the client code to reattempt the open with a smaller memory request.

Windows 95/98/ME AUX Denial of Service

Description:

When running on Windows 95/98/ME, URLs requested with path components matching a set of reserved DOS device names caused the WebServer to crash.

The names that cause the crash are:

aux
con
nul
clock$
config$

Fix:

Code added to the websValidateUrl() function to check the contents of the parsed URL against the list of prohibited names. If any of those names are present in the parsed URL, the URL is rejected as invalid.

The code that checks for these prohibited pathname components checks for them in the form of either:

http://<<server address>>/aux

or:

http://<<server address>>/aux:

where any non-alphanumeric character following one of the prohibited names will cause the URL request to be rejected.

404 Cross-site Scripting Exploit

Description:

Malicious users could request an invalid URL containing embedded JavaScript code that would be executed in the user's browser.

Fix:

404 (and other error messages) returned by the WebServer no longer display the invalid URL.

Long URL Overflow Crash

Description:

URLs containing more than 64 levels of path components caused the WebServer to crash, entering a buffer overflow condition.

Fix:

The WebServer now keeps track of the depth as it validates the URL. URLs that are too long are now rejected with an error message.

Incorrect Error Code in security.c

Description:

Pages assigned an access level of AM_NONE should return an error code of 404 instead of 400 when an attempt it made to access them.

Fix:

Error code corrected.

Pragma Code for RISC Architectures

Description:

A pragma was not set correctly when compiling for SPARC machines.

Fix:

Code added to uemf.h:

#ifdef sparc
# define __NO_PACK
#endif /* sparc */

Fixed vulnerability to malicious code in webs.c

Summary:

There were two vulnerabilities in webs.c. Sending a POST message with a content-length but no data resulted in an attempt to perform a strlen() on a NULL pointer (thanks to Richard Cullen). Also, sending an HTTP POST message with a Content-Length header indicating that the length of the posted data was less than zero would crash the server (thanks to Auriemma Luigi).

Fix:

Code errors corrected.

https:// bug in security handler

Summary:

The websSecurityHandler() function was performing a logical OR: (flags | WEBS_SECURE) instead of a logical AND (flags & WEBS_SECURE), leading to incorrect results (thanks to "Dhanwa T").

Fix:

Code errors corrected.

Fixed vulnerability to malicious code in sockGen.c

Summary:

At line 613 of sockGen.c, the return value of the function socketInputBuffered() was being discarded, leading to incorrect behavior in some cases. (Thanks to Richard Cullen)

Fix:

Code errors corrected.

Directory Traversal Exploit

Summary:

Several sources have reported that requesting an URL with URL-encoded backslashes (%5C) allow accessing files located outside the server's designated web root. This should only have been possible on Windows, as URL-encoded forward slashes (%2F) were already being handled correctly.

Fix:

Modified default.c so that any backslash characters created as part of decoding the URL string are converted (in place) to forward slashes. The pre-existing directory-traversal detection code then rejects the bad URL as expected.

MIME type for external JavaScript files

Summary:

The WebServer would not serve external JavaScript files (*.js) correctly.

Fix:

modified mime.c to associate .js files with the MIME type application/x-javascript.

Bug in If-Modified-Since parsing

Summary:

There was an off-by-one error when converting from Gregorian date to time_t.

Fix:

modified function dateToTimet in file webs.c. The month parameter is numbered from 0 (Jan == 0), but FixedFromGregorian() takes months numbered from 1 (January == 1). We need to add 1 to the month before calling FixedFromGregorian.

Ejscript Error Messages

Summary:

Changed ejEval() function so it displays in the browser the error string that is reported by the ejScript interpreter (old code discarded it completely).

Fix:

modified websuemf.c

Security Handler Response Codes

Summary:

Several places in the websSecurityHandler() function were returning error code 200 (success) instead of the correct 400-level error code.

Fix:

Corrected error codes in security.c

Security Handler Memory Leak

Summary:

In websSecurityHandler(), if the WebServer was compiled with WEBS_SSL_SUPPORT enabled, there was a return path that leaked memory.

Fix:

Added call to bfree(B_L, accessLimit);

Ejscript Write Corruption

Summary:

Very long text strings passed to the Ejscript write() function were being corrupted before being displayed.

Fix:

Commented out a trace() statement in ejGetLexToken() that appears to have been the culprit. The value of ep->token was being corrupted somewhere in the trace.

Error in dsnprintf(): "%X" format

Summary:

The "%X" format specifier did not correctly cause the function to output uppercase hexadecimal digits.

Fix:

Added support for the "%X" format specifier.

BUG018565 Re-fixed

Summary:

See 2.1.1 release notes (below). This bug fix did not make it into the 2.1.1 release.

Fix:

Corrected code in sockGen.c.

Potential Error in error()

Summary:

If error() is called where the etype parameter is not E_LOG, E_ASSERT, or E_USER, the call to bfreeSafe(B_L, buf) now at line 71 will fail, because 'buf' is randomly initialized.

Fix:

We format a message saying that this is an unknown message type, and in doing so give buf a valid value.

Added Support For Customized Access Control

Summary:

Several users requested a method to control URL access in a hierarchical fashion. For example, users assigned to an 'admin' group might have access to all URLs on the WebServer, and users assigned to the group 'technician' would have access to a smaller set of pages, and users assigned to the group 'users' would perhaps only have access to a set of read-only pages. The built-in WebServer access control system only allows users to access URLs that exactly match their group membership.

Fix:

Added call to a user-supplied function `` bool_t dmfCanAccess(const char_t* userGroup, const char_t* group)``. This function is called from inside umUserCanAccessURL() if the macro qHierarchicalAccess is defined.

Memory Leak in websParseRequest()

Summary:

Memory was being leaked in the code now at line 907 of webs.c.

Fix:

Added a call to bfree().

Intermittent Access Error for CGI Scripts (BUG01937)

Summary:

Pages were occasionally replaced with the message, Access Error: Data follows when trying to obtain CGI generated no output.

Fix:

On multiple CPU systems, it is possible for a CGI application to exit before its output is flushed to disk. The change for this release locates the code that collects the output from the CGI application in a separate routine. In addition to calling that routine from within the CGI application processing loop, it is also called in a brief loop after the CGI application has exited. This extra loop runs for only up to one second while the collected output remains empty. If, after 1 second, the output remains empty, the original course of action is followed (Access Error is reported).

CPU Utilization Hangs at 100% on a Socket Disconnect (BUG01865)

Summary:

This error occurs whenever a user terminates a request before the server has had ample time to service it. This can be simulated by quickly hitting the refresh button on the browser twice in a row, causing the first request to be terminated. The server then enters into a tight loop that utilizes all of its time.

Fix:

Always close the socket prior to a disconnect.

Security Features can be Bypassed by Adding an Extra Slash in the URL (BUG01518)

Summary:

By adding an extra slash in a URL, password prompting is bypassed, allowing unrestricted access to secured pages.

Fix:

Remove multiple adjacent occurrences of slashes in the URL before passing it to the security handler.

Call to websSetVar causes a crash (BUG01938)

Summary:

Whenever a request is not completed while being processed by websGetInput(), a call to websDone is made, followed by an attempt to process the partial request data.

Fix:

Return immediately after closing the socket.

Remove stray semicolon in emfdb.c (BUG01820)

Summary and Fix:

A stray semicolon was removed from this file.