[VulnWatch] arc insecure temporary file creation

From: ZATAZ Audits (exploits_at_zataz.net)
Date: 09/16/05

  • Next message: ZATAZ Audits: "[VulnWatch] Message for D1g1t4lLeech ZATAZ Audit has discovered this bug the 2005-09-05 D1g1t4lLeech you are a true Leecher ;)"
    Date: Fri, 16 Sep 2005 16:06:22 +0200
    To: vuldb@securityfocus.com, vuln@secunia.com, vuln@k-otik.com, moderators@osvdb.org, bugs@securitytracker.com, submissions@packetstormsecurity.org, news@securiteam.com, xforce@iss.net, bugtraq@securityfocus.com, vulnwatch@vulnwatch.org, full-disclosure@lists.grok.org.uk
    
    

    #########################################################

    arc insecure temporary file creation

    Vendor: http://arc.sourceforge.net/
    Advisory: http://www.zataz.net/adviso/arc-09052005.txt
    Vendor informed: yes
    Exploit available: yes
    Impact : low
    Exploitation : low

    #########################################################

    The vulnerability is caused due to temporary file being created insecurely.
    The temporary file used for archive creation could be read by untrusted
    users.

    Secunia has reported that D1g1t4lLeech has discovered this bug the
    2005-09-16.

    ZATAZ Audit has discovered this bug the 2005-09-05

    D1g1t4lLeech you are a true Leecher ;)

    ##########
    Versions:
    ##########

    arc <= 5.21j

    ##########
    Solution:
    ##########

    No solutions

    #########
    Timeline:
    #########

    Discovered : 2005-09-05
    Vendor notified : no time to report (Leech powa)
    Vendor response : no reponse
    Vendor fix : no patch
    Vendor Sec report (vendor-sec@lst.de) :
    Disclosure : 2005-09-19

    #####################
    Technical details :
    #####################

    Vulnerable code :
    -----------------

    In arc.c :

    210 /* see where temp files go */
    211 #if !_MTS
    212 arctemp = calloc(1, STRLEN);
    213 if (!(arctemp2 = envfind("ARCTEMP")))
    214 arctemp2 = envfind("TMPDIR");
    215 if (arctemp2) {
    216 strcpy(arctemp, arctemp2);
    217 n = strlen(arctemp);
    218 if (arctemp[n - 1] != CUTOFF)
    219 arctemp[n] = CUTOFF;
    220 }
    221 #if UNIX
    222 else strcpy(arctemp, "/tmp/");
    223 #endif
    224 #if !MSDOS
    225 {
    226 static char tempname[] = "AXXXXXX";
    227 strcat(arctemp, mktemp(tempname));
    228 }
    229 #else
    230 strcat(arctemp, "$ARCTEMP");
    231 #endif
    232 #else
    233 guinfo("SHFSEP ", gotinf);
    234 sepchr[0] = gotinf[0];
    235 guinfo("SCRFCHAR", gotinf);
    236 tmpchr[0] = gotinf[0];
    237 arctemp = "-$$$";
    238 arctemp[0] = tmpchr[0];
    239 #endif
    240 arctemp2 = NULL;
    241
    242 #if !UNIX
    243 /* avoid any case problems with arguments */
    244
    245 for (n = 1; n < num; n++) /* for each argument */
    246 upper(arg[n]); /* convert it to uppercase */
    247 #else
    248 /* avoid case problems with command options */
    249 upper(arg[1]); /* convert to uppercase */
    250 #endif
    251
    252 /* create archive names, supplying defaults */
    253 #if UNIX
    254 if (!stat(arg[2],&sbuf)) {
    255 if ((sbuf.st_mode & S_IFMT) == S_IFDIR)
    256 makefnam(arg[2],".arc",arcname);
    257 else
    258 strcpy(arcname,arg[2]);
    259 } else
    260 makefnam(arg[2],".arc",arcname);
    261 #else
    262 makefnam(arg[2], ".ARC", arcname);
    263 #endif

    Take a look on a the right off temporary files in /tmp :

    -rw-r--r-- 1 root root 1564 Sep 5 10:28 A3C6Zs4.arc

    The file should not be world readable.

    The same problem for marc.c

    #########
    Related :
    #########

    Bug report :
    CVE :

    #####################
    Credits :
    #####################

    Eric Romang (eromang@zataz.net - ZATAZ Audit)
    Thxs to Gentoo Security Team. (Taviso, jaervosz, solar, Koon, etc.)


  • Next message: ZATAZ Audits: "[VulnWatch] Message for D1g1t4lLeech ZATAZ Audit has discovered this bug the 2005-09-05 D1g1t4lLeech you are a true Leecher ;)"

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