Exim 4.72 and earlier allows local users to gain privileges by leveraging the ability of the exim user account to specify an alternate configuration file with a directive that contains arbitrary commands, as demonstrated by the spooldirectory directive.
Description of problem: The handling functions for sending and receiving messages, in rdspagecopyuser(), use the unchecked copyuserinatomic functions without any access checks on user-provided pointers. As a result, by passing a kernel address as an iovec base address in recvmsg-style calls, a local user can overwrite arbitrary kernel memory, which can easily be used to escalate privileges to root.
Introduced via 7875e18e (v2.6.30-rc1).
Acknowledgements:
Red Hat would like to thank Dan Rosenberg of Virtual Security Research for reporting this issue.
Description of problem:
When parsing a peer's supported HMAC authentication options in the sctpauthasocgethmac() function, a malicious peer can craft their HMAC array in such a way as to cause memory corruption (out-of-bounds read followed by use of retrieved out-of-bounds data), which at the very least could cause a denial of service via kernel panic, and possibly worse. It appears this could be triggered remotely when connecting to a malicious peer, or locally by a user acting as both endpoints. In both cases, the "authenable" sysctl must be set in order to trigger the bug.
References: http://marc.info/?l=oss-security&m=128619854321910&w=1 http://marc.info/?l=linux-kernel&m=128596992418814&w=2
Description of problem: sctppacketconfig() is called when getting the packet ready for appending of chunks. The function should not touch the current state, since it's possible to ping-pong between two transports when sending, and that can result packet corruption followed by skb overlfow crash.
Upstream commit: http://git.kernel.org/linus/4bdab43323b459900578b200a4b8cf9713ac8fab
Reference: http://marc.info/?l=linux-netdev&m=128453869227715&w=3 http://www.spinics.net/lists/linux-sctp/msg01051.html
Essentially, we are resetting the contents of the packet when it's not empty.
Stack-based buffer overflow in the (1) sidparse and (2) domsidparse functions in Samba before 3.5.5 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted Windows Security ID (SID) on a file share.
Buffer overflow in the niugetethtooltcamall function in drivers/net/niu.c in the Linux kernel before 2.6.36-rc4 allows local users to cause a denial of service or possibly have unspecified other impact via the ETHTOOLGRXCLSRLALL ethtool command.
Description of problem: There is a bug in sndseqossopen from sound/core/seq/oss/seqossinit.c. So here's the error path for some setup failure:
error: sndseqosswriteqdelete(dp->writeq); sndseqossreadqdelete(dp->readq); sndseqosssynthcleanup(dp); sndseqossmidicleanup(dp); deleteport(dp); deleteseqqueue(dp->queue); kfree(dp);
This looks okay, but actually, deleteport calls portdelete (eventually... this code is tough to follow) which does a freedevinfo on the owner struct seqossdevinfo, here (around ~269 in seqports.c):
if (port->privatefree) port->privatefree(port->privatedata);
because of this (around ~334 in seqossinit.c):
memset(&callback, 0, sizeof(callback)); callback.owner = THISMODULE; callback.privatedata = dp; callback.eventinput = sndseqosseventinput; callback.privatefree = freedevinfo; port.kernel = &callback;
Which does this:
static void freedevinfo(void private) { struct seqossdevinfo dp = (struct seqossdevinfo )private;
if (dp->timer) sndseqosstimerdelete(dp->timer); if (dp->writeq) sndseqosswriteqdelete(dp->writeq);
if (dp->readq) sndseqossreadqdelete(dp->readq); kfree(dp); }
So.....
deleteport(dp); deleteseqqueue(dp->queue); <= Oops, dereferencing released pointer. kfree(dp); <= Oops, double free.
Acknowledgements:
Red Hat would like to thank Tavis Ormandy for reporting this issue.
Description of problem: Reported by Taviso Ormandy via the Ubuntu Security Team.
$ gcc keyctl.c -o keyctl -lkeyutils $ ./keyctl [ 213.999221] BUG: unable to handle kernel NULL pointer dereference at 00000034 [ 214.002770] IP: [<c02f0f2a>] keyctlsessiontoparent+0x12a/0x1c0 [ 214.006011] pde = 0fdb0067 pte = 00000000 [ 214.008007] Oops: 0000 [#1] SMP [ 214.008973] last sysfs file: /sys/module/ppdev/initstate [ 214.010466] Modules linked in: binfmtmisc vmblock vsock vmmemctl vmhgfs acpiphp sndens1371 gameport sndac97codec ac97bus sndpcmoss sndmixeross sndpcm sndseqdummy sndseqoss sndseqmidi sndrawmidi sndseqmidievent sndseq sndtimer sndseqdevice ppdev fbcon tileblit font bitblit softcursor snd psmouse serioraw parportpc soundcore sndpagealloc vmci shpchp i2cpiix4 vga16fb vgastate intelagp agpgart lp parport mptspi mptscsih mptbase floppy scsitransportspi vmxnet [ 214.024416] [ 214.024899] Pid: 1772, comm: a.out Not tainted (2.6.32-24-generic #41-Ubuntu) VMware Virtual Platform [ 214.027413] EIP: 0060:[<c02f0f2a>] EFLAGS: 00210046 CPU: 0 [ 214.028927] EIP is at keyctlsessiontoparent+0x12a/0x1c0 [ 214.030419] EAX: d2cde100 EBX: d2cdeb00 ECX: 000003e8 EDX: cfcfc480 [ 214.032132] ESI: cfddb300 EDI: 00000000 EBP: d2c33f94 ESP: d2c33f7c [ 214.033811] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 [ 214.035292] Process a.out (pid: 1772, ti=d2c32000 task=d79bbfc0 task.ti=d2c32000) [ 214.037346] Stack: [ 214.037926] 00000000 000003e8 d2cde700 004370c0 00000012 08048520 d2c33fac c02f22e5 [ 214.040262] <0> 00000004 00000012 00327ff4 08048520 d2c32000 c01033ec 00000012 004370c0 [ 214.042795] <0> 0804852b 00327ff4 08048520 00000001 00000120 0000007b 0000007b 00000000 [ 214.045405] Call Trace: [ 214.046108] [<c02f22e5>] ? syskeyctl+0x65/0x170 [ 214.047434] [<c01033ec>] ? syscallcall+0x7/0xb [ 214.048711] Code: 90 0f 85 77 ff ff ff 8b 7a 08 89 7d ec 3b 78 18 0f 85 68 ff ff ff 3b 7a 18 0f 85 5f ff ff ff 3b 7a 10 0f 85 56 ff ff ff 8b 7d e8 <3b> 4f 34 8d 76 00 0f 85 47 ff ff ff 8b 7d f0 3b 4f 34 0f 85 3b [ 214.056401] EIP: [<c02f0f2a>] keyctlsessiontoparent+0x12a/0x1c0 SS:ESP 0068:d2c33f7c [ 214.058676] CR2: 0000000000000034 [ 214.059605] ---[ end trace cc41d96061101854 ]---
Description of problem: This series closes a recently discovered problem in XFS filehandle conversion. On systems where inodes are dynamically deleted, XFS does not adequately verify the inode numbers in the filehandles, which results in reading stale inodes from disk and potentially returning them as valid files. Because these unlinked inodes were never zeroed out when the chunk was deallocated, some inodes in the chunk can still appear to have to data extents attached to them. This can lead to stale data exposure, exposure of active data and potentially overwriting of active data if the stale extents referenced in the unlinked inodes have been re-allocated.
Both NFS filehandles and local filehandles provided through libhandle have this same problem. libhandle requires root permissions to use the interface, so it is not exposing information that you can't get more easily with other means (e.g. xfsdb or reading directly form the block device), so there isn't really an issue here.
For NFS, we may incorrectly accept stale file handles for unlinked inodes after a server reboot if the unlinked inodes have not been overwritten leading to the above issues being triggered if multiple NFS clients are accessing the same files.
Christoph's make-bulkstat-coherent patch is the basis for this series as bulkstat can also expose unlinked inodes and information about them back to userspace as it makes the same assumptions about inode lookups as the file handle interfaces.
As a result, the first two patches of the series make up the real bug fix. The last two patches make it clear we are lookuping up untrusted inode numbers and clear away a shortcut that these interfaces used that we do not want used any more. Hence for backports to other kernels, only the first two patches are necessary.
The test program that demonstrates the issue via the openbyhandle interface can be found here:
http://oss.sgi.com/archives/xfs/2010-06/msg00191.html
Version 2: - removed useless ip->iimap.imblkno initialisation in xfsiread() - reworked a comment refering to bulkstat when it should refer to untrusted inodes. - removed typedefs from xfsimaplookup() - killed useless error logging from xfsimaplookup() - rearranged the logic flow of xfsimaplookup() to remove the gotos.
[PATCH 0/4, V2] xfs: validate inode numbers in file handles correctly http://article.gmane.org/gmane.comp.file-systems.xfs.general/33767
[PATCH 1/4] xfs: always use iget in bulkstat http://article.gmane.org/gmane.comp.file-systems.xfs.general/33770
[PATCH 2/4] xfs: validate untrusted inode numbers during lookup http://article.gmane.org/gmane.comp.file-systems.xfs.general/33771
[PATCH 3/4] xfs: rename XFSIGETBULKSTAT to XFSIGETUNTRUSTED http://article.gmane.org/gmane.comp.file-systems.xfs.general/33768
[PATCH 4/4] xfs: remove block number from inode lookup code http://article.gmane.org/gmane.comp.file-systems.xfs.general/33769
[PATCH] xfsqa: test openbyhandle() on unlinked and freed inode cluster http://oss.sgi.com/archives/xfs/2010-06/msg00191.html
Description of problem: The problem was in the way the gfs2 directory code was trying to re-use sentinel directory entries.
In the failing case, gfs2's rename function was renaming a file to another name that had the same non-trivial length. The file being renamed happened to be the first directory entry on the leaf block.
First, the rename code (gfs2rename in opsinode.c) found the original directory entry and decided it could do its job by simply replacing the directory entry with another. Therefore it determined correctly that no block allocations were needed.
Next, the rename code deleted the old directory entry prior to replacing it with the new name. Therefore, the soon-to-be replaced directory entry was temporarily made into a directory entry "sentinel" or a place holder at the start of a leaf block.
Lastly, it went to re-add the replacement directory entry in that leaf block. However, when gfs2direntfindspace was looking for space in the leaf block, it used the wrong value for the sentinel. That threw off its calculations so later it decides it can't really re-use the sentinel and therefore must allocate a new leaf block. But because it previously decided to re-use the directory entry, it didn't waste the time to grab a new block allocation for the inode. Therefore, the inode's ialloc pointer was still NULL and it crashes trying to reference it.
In the case of sentinel directory entries, the entire dirent is reused, not just the "free space" portion of it, and therefore the function gfs2direntfindspace should use the value 0 rather than GFS2DIRENTSIZE(0) for the actual dirent size.
Fixing this calculation enables the reproducer programs to work properly.
Sauli Pahlman of CERT-FI provided us with fuzzed PDF file which causes xpdf / poppler PDF parser to crash.
The crash is caused by an attempt to dereference uninitialized Gfx::parser pointer in Gfx::getPos(), which assumes parser is either NULL or valid Parser pointer.
http://cgit.freedesktop.org/poppler/poppler/tree/poppler/Gfx.cc?id=71063d51#n879
Description of problem: CVE-2009-3553 (bug #530111) has not been completely fixed.
Version-Release number of selected component (if applicable): Versions known to be affected:
cups-1.3.7-11.el54.5 (RHEL-5.4.z) cups-1.3.7-16.el5 (RHEL-5)
Additional info: The cause is that the cupsdDoSelect() function uses one of several implementations depending on the underlying select/poll capabilities of the operating system. For kqueue and epoll implementations, cupsdRemoveSelect() does not immediately decrease the reference count for the file descriptor and instead adds it to the cupsdinactivefds array. File descriptors in that array are finally dereferenced in cupsdStopSelect() (i.e. program termination).
In Red Hat Enterprise Linux, the epoll implementation is used.
The previous fix for CVE-2009-3553 was to check that another reference was held for the file descriptor before calling the writecb function; however, that will always be the case for both the epoll and kqueue implementations.
The correct fix is to check whether the file descriptor is in the cupsdinactivefds array before calling the writecb function.
The personality subsystem in the Linux kernel before 2.6.31-rc3 has a PERCLEARONSETID setting that does not clear the ADDRCOMPATLAYOUT and MMAPPAGEZERO flags when executing a setuid or setgid program, which makes it easier for local users to leverage the details of memory usage to (1) conduct NULL pointer dereference attacks, (2) bypass the mmapminaddr protection mechanism, or (3) defeat address space layout randomization (ASLR).
The streamreqbodycl function in modproxyhttp.c in the modproxy module in the Apache HTTP Server before 2.3.3, when a reverse proxy is configured, does not properly handle an amount of streamed data that exceeds the Content-Length value, which allows remote attackers to cause a denial of service (CPU consumption) via crafted requests.
François Guerraz reported in Debian BTS a possible DoS (CPU consumption) a DoS with moddeflate since it does not stop to compress large files even after the network connection has been closed. This allows to use large amounts of CPU if there is a largish file available that has moddeflate enabled.
Original report: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=534712
Post to the apache-httpd-dev mailing list: http://marc.info/?l=apache-httpd-dev&m=124621326524824&w=2
The expat XML parser in the aprxml interface in xml/aprxml.c in Apache APR-util before 1.3.7, as used in the moddav and moddavsvn modules in the Apache HTTP Server, allows remote attackers to cause a denial of service (memory consumption) via a crafted XML document containing a large number of nested entity references, as demonstrated by a PROPFIND request, a similar issue to CVE-2003-1564.
Multiple buffer overflows in the cifs subsystem in the Linux kernel before 2.6.29.4 allow remote CIFS servers to cause a denial of service (memory corruption) and possibly have unspecified other impact via (1) a malformed Unicode string, related to Unicode string area alignment in fs/cifs/sess.c; or (2) long Unicode characters, related to fs/cifs/cifssmb.c and the cifsreaddir function in fs/cifs/readdir.c.
A privilege escalation flaw was found in the way udev used to check for the origin of messages sent from the NETLINK service. An attacker could use this flaw to escalate his privileges by sending the NETLINK message from userspace process, instead of from the kernel.
Acknowledgements:
Red Hat would like to thank Sebastian Krahmer of the SUSE Security Team for responsibly reporting this flaw.
Common Vulnerabilities and Exposures assigned an identifier CVE-2007-5191 to the following vulnerability:
mount and umount in util-linux call the setuid and setgid functions in the wrong order and do not check the return values, which might allow attackers to gain privileges via helpers such as mount.nfs.
References: http://git.kernel.org/?p=utils/util-linux-ng/util-linux-ng.git;a=commit;h=ebbeb2c7ac1b00b6083905957837a271e80b187e
Multiple integer overflows in PHP 4 before 4.4.8, and PHP 5 before 5.2.4, allow remote attackers to obtain sensitive information (memory contents) or cause a denial of service (thread crash) via a large len value to the (1) strspn or (2) strcspn function, which triggers an out-of-bounds read. NOTE: this affects different product versions than CVE-2007-3996.
Buffer overflow in the safernamesuffix function in GNU tar has unspecified attack vectors and impact, resulting in a "crashing stack."
Integer signedness error in the gssrpcsvcauthunix function in svcauthunix.c in the RPC library in MIT Kerberos 5 (krb5) 1.6.1 and earlier might allow remote attackers to execute arbitrary code via a negative length value.
Net::DNS before 0.60, a Perl module, allows remote attackers to cause a denial of service (stack consumption) via a malformed compressed DNS packet with self-referencing pointers, which triggers an infinite loop.
Logic error in the SID/Name translation functionality in smbd in Samba 3.0.23d through 3.0.25pre2 allows local users to gain temporary privileges and execute SMB/CIFS protocol operations via unspecified vectors that cause the daemon to transition to the root user.
Buffer overflow in the bundled libxmlrpc library in PHP before 4.4.7, and 5.x before 5.2.2, has unknown impact and remote attack vectors.
Buffer overflow in the sqlitedecodebinary function in the bundled sqlite library in PHP 4 before 4.4.5 and PHP 5 before 5.2.1 allows context-dependent attackers to execute arbitrary code via an empty value of the in parameter, as demonstrated by calling the sqliteudfdecodebinary function with a 0x01 character.
Buffer overflow in the gdImageStringFTEx function in gdft.c in GD Graphics Library 2.0.33 and earlier allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code via a crafted string with a JIS encoded font.
OpenLDAP before 2.3.29 allows remote attackers to cause a denial of service (daemon crash) via LDAP BIND requests with long authcid names, which triggers an assertion failure.
The clipmkip function in net/atm/clip.c of the ATM subsystem in Linux kernel allows remote attackers to cause a denial of service (panic) via unknown vectors that cause the ATM subsystem to access the memory of socket buffers after they are freed (freed pointer dereference).
The nlmclntmarkreclaim in clntlock.c in NFS lockd in Linux kernel before 2.6.16 allows remote attackers to cause a denial of service (process crash) and deny access to NFS exports via unspecified vectors that trigger a kernel oops (null dereference) and a deadlock.