apachetop insecure temporary file creation

[ZATAZ Audits <exploits () zataz net>]

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apachetop insecure temporary file creation

Vendor: http://clueful.shagged.org/apachetop/
Advisory: http://www.zataz.net/adviso/apachetop-09022005.txt
Vendor informed: yes
Exploit available: yes
Impact : low
Exploitation : low

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The vulnerability is caused due to temporary file being created insecurely.
This can be exploited via symlink attacks in combination  to create and 
overwrite arbitrary files with the privileges of the user running the 
affected script.

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Versions:
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apachetop <= 0.12.5

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Solution:
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Apply : apachetop_CAN-2005-2660.patch
Patch from Steve Kemp (Debian)
http://bugs.gentoo.org/attachment.cgi?id=69342

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Timeline:
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Discovered : 2005-09-02
Vendor notified : 2005-09-02
Vendor response : no reponse
Vendor fix : no patch
Vendor Sec report (vendor-sec () lst de) : 2005-09-13
Disclosure : 2005-09-30

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Technical details :
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Vulnerable code :
-----------------

ake a look at : src/apachetop.h

247 #define DEBUG_OUTPUT "/tmp/atop.debug"

Then in : src/apachetop.cc

85         cf.debug = true;

1103 int dprintf(const char *fmt, ...) /* {{{ */
1104 {
1105         FILE *d;
1106         va_list args;
1107
1108         if (cf.debug && (d = fopen(DEBUG_OUTPUT, "a")))
1109         {
1110                 va_start(args, fmt);
1111                 vfprintf(d, fmt, args);
1112                 fclose(d);
1113                 va_end(args);
1114         }
1115
1116         return 0;
1117 } /* }}} */

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Related :
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Bug report : http://bugs.gentoo.org/show_bug.cgi?id=104473
CVE : CAN-2005-2660

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Credits :
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Eric Romang (eromang () zataz net - ZATAZ Audit) - Gentoo security scout
Thxs to Gentoo Security Team.