[UNIX] ekg Insecure Temporary Files Creation Vulnerability

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  ekg Insecure Temporary Files Creation Vulnerability
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SUMMARY

 <http://dev.null.pl/ekg> ekg is "a Gadu-Gadu client". ekg creates 
temporary files in an insecure way, allowing local attackes to gain 
elevated privileges via a symblink attack.

DETAILS

Vulnerable Systems:
 * ekg versions released before 2005-06-05

The vulnerability is caused due to temporary files being created 
insecurely. This can be exploited via a symlink attack, and in turn create 
and/or overwrite arbitrary files with the privileges of the user running 
the affected script.

Vulnerable code:
In contrib/scripts/linki.py
95 def czyjest ():
96   if os.path.exists('/tmp/rmrmg_ekg_url'):
97     wejsc= open ('/tmp/rmrmg_ekg_url')
98     file = wejsc.readlines()
99     dlug=len(file)
100     wejsc.close()
101     #ekg.printf("generic", "liczno  %d" %(dlug))
102     return file
103   else:
104     return 0

Then
35 def handle_keypress(meta, key):
36   if key == 269:
37     ekg.printf("generic", "wci nieto F5")
38     nurl=czyjest()
39     if nurl == 0:
40       ekg.printf("generic", "nie ma zadnego adresu URL")
41     else:
42       dlug=len(nurl)
43       if dlug == 1:
44         ekg.printf("generic", "otwieram %s w nowej zak adce" 
%(nurl[0]))
45         os.system("MozillaFirebird -remote 'openURL(%s,new-tab)'" 
%(nurl[0]))
46         os.system('rm /tmp/rmrmg_ekg_url')
47       else:
48         ekg.printf("generic", "link w mam %d" %(dlug))
49         wielejest(nurl)
50         ekg.printf("generic", "otwieram %s w nowej zak adce" 
%(nurl[0]))
51         os.system("MozillaFirebird -remote 'openURL(%s, new-tab)'" 
%(nurl[0]))
52   elif key == 270:
53     ekg.printf("generic", "wcisni to F6")
54     nurl=czyjest()
55     if nurl == 0:
56       ekg.printf("generic", "nic nie moge skasowa - nie mazadnego 
adresu URL")
57     else:
58       dlug=len(nurl)
59       if dlug == 1:
60         ekg.printf("generic", "kasuje adres %s" %(nurl[0]))
61         os.system('rm /tmp/rmrmg_ekg_url')
62       else:
63         ekg.printf("generic", "jest wiele link w")
64         wielejest(nurl)
65         ekg.printf("generic", "kasuje pierwszy czyli: %s"%(nurl[0]))
66   elif key == 271:
67     ekg.printf("generic", "wcisni to F7")
68     nurl=czyjest()
69     if nurl == 0:
70       ekg.printf("generic", "nie ma zadnego adresu URL")
71     else:
72       dlug=len(nurl)
73       if dlug == 1:
74         ekg.printf("generic", "otwieram %s w nowym oknie"%(nurl[0]))
75         os.system("MozillaFirebird %s" %(nurl[0]))
76         os.system('rm /tmp/rmrmg_ekg_url')
77       else:
78         ekg.printf("generic", "link w mam %d" %(dlug))
79         wielejest(nurl)
80         ekg.printf("generic", "otwieram %s w nowym oknie"%(nurl[0]))
81   elif key == 272:
82     ekg.printf("generic", "wcisni to F8")
83     nurl=czyjest()
84     ekg.printf("generic", "F5 - otwiera w nowej zak adce; F7 wnowym 
oknie, a F6 kasuje, wszystko tyczy si pierwszej po zycji zlisty")
85     if nurl == 0:
86       ekg.printf("generic", "nie ma zadnego adresu URL")
87     else:
88       dlug=len(nurl)
89       ekg.printf("generic", "link w mam %d oto one:" %(dlug))
90       for po in nurl:
91         ekg.printf("generic", "%s" %(po))
92   return 1

CVE Information:
 <http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2005-1916> 
CAN-2005-1916


ADDITIONAL INFORMATION

The information has been provided by  <mailto:exploits@xxxxxxxxx> ZATAZ 
Audits.
The original article can be found at:  
<http://www.zataz.net/adviso/ekg-06062005.txt> 
http://www.zataz.net/adviso/ekg-06062005.txt
The original article can be found at:  
<http://bugs.gentoo.org/show_bug.cgi?id=94172> 
http://bugs.gentoo.org/show_bug.cgi?id=94172



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