general/7434: Buffer overflow in http_main.c

[Yogesh Girdhar <gi...@rpi.edu>]

>Number:         7434
>Category:       general
>Synopsis:       Buffer overflow in http_main.c
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    apache
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   apache
>Arrival-Date:   Mon Mar 19 20:40:00 PST 2001
>Closed-Date:
>Last-Modified:
>Originator:     girdhy@rpi.edu
>Release:        All
>Organization:
apache
>Environment:
All OSes
>Description:
Inside http_main.c we have the following function declaration:
---------------------------------
static void usage(char *bin)
{
    char pad[MAX_STRING_LEN];
    unsigned i;
 
    for (i = 0; i < strlen(bin); i++)
    pad[i] = ' ';                             //<<<------Buffer overflow
    pad[i] = '\0';
-------------------------

Call to this function is made from a lot of places like this:

---------------------
 case 'h':
     usage(argv[0]);
 case '?':
     usage(argv[0]);
---------------------
MAX_STRING_LEN has a size of 8k.
Although argv[0] will be less that 1k on most shells, but if somebody writes a custom shell or if somebody calles apache through exec() with an argv[0] size of greater than 8k then apache will crash.
This problem isn't really a big security threat but still its a bug which needs to be fixed :)
>How-To-Repeat:
If somebody writes a custom shell or if somebody calls apache through exec() with an argv[0] size of greater than 8k then apache will crash.
>Fix:
it can be fixed doing the following in ur usage()
  if(strlen(bin)>=MAX_STRING_LEN) 
     bin += strlen(bin)-(MAX_STRING_LEN+1); // bin is now a string containing the last 8k characters of the original bin.
>Release-Note:
>Audit-Trail:
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