3571e53040
patches for easier mirroring, to eliminate a special copy, to make www.freebsd.org/security a full copy of security.freebsd.org and be eventually be the same. For now files are just sitting there. The symlinks are missing. Discussed on: www (repository location) Discussed with: simon (so)
150 lines
6 KiB
Text
150 lines
6 KiB
Text
-----BEGIN PGP SIGNED MESSAGE-----
|
|
Hash: SHA1
|
|
|
|
=============================================================================
|
|
FreeBSD-SA-08:03.sendfile Security Advisory
|
|
The FreeBSD Project
|
|
|
|
Topic: sendfile(2) write-only file permission bypass
|
|
|
|
Category: core
|
|
Module: sys_kern
|
|
Announced: 2008-02-14
|
|
Credits: Kostik Belousov
|
|
Affects: All supported versions of FreeBSD
|
|
Corrected: 2008-02-14 11:45:00 UTC (RELENG_7, 7.0-PRERELEASE)
|
|
2008-02-14 11:45:41 UTC (RELENG_7_0, 7.0-RELEASE)
|
|
2008-02-14 11:46:08 UTC (RELENG_6, 6.3-STABLE)
|
|
2008-02-14 11:46:41 UTC (RELENG_6_3, 6.3-RELEASE-p1)
|
|
2008-02-14 11:47:06 UTC (RELENG_6_2, 6.2-RELEASE-p11)
|
|
2008-02-14 11:47:39 UTC (RELENG_6_1, 6.1-RELEASE-p23)
|
|
2008-02-14 11:49:39 UTC (RELENG_5, 5.5-STABLE)
|
|
2008-02-14 11:50:28 UTC (RELENG_5_5, 5.5-RELEASE-p19)
|
|
CVE Name: CVE-2008-0777
|
|
|
|
For general information regarding FreeBSD Security Advisories,
|
|
including descriptions of the fields above, security branches, and the
|
|
following sections, please visit <URL:http://security.FreeBSD.org/>.
|
|
|
|
I. Background
|
|
|
|
The sendfile(2) system call allows a server application (such as a
|
|
HTTP or FTP server) to transmit the contents of a file over a network
|
|
connection without first copying it to application memory. High
|
|
performance servers such as the Apache HTTP Server and ftpd use sendfile.
|
|
|
|
II. Problem Description
|
|
|
|
When a process opens a file (and other file system objects, such as
|
|
directories), it specifies access flags indicating its intent to read,
|
|
write, or perform other operations. These flags are checked against
|
|
file system permissions, and then stored in the resulting file
|
|
descriptor to validate future operations against.
|
|
|
|
The sendfile(2) system call does not check the file descriptor access
|
|
flags before sending data from a file.
|
|
|
|
III. Impact
|
|
|
|
If a file is write-only, a user process can open the file and use
|
|
sendfile to send the content of the file over a socket, even though the
|
|
user does not have read access to the file, resulting in possible
|
|
disclosure of sensitive information.
|
|
|
|
IV. Workaround
|
|
|
|
No workaround is available, but systems are only vulnerable if
|
|
write-only files exist, which are not widely used.
|
|
|
|
V. Solution
|
|
|
|
Perform one of the following:
|
|
|
|
1) Upgrade your vulnerable system to 5-STABLE, 6-STABLE, or
|
|
7.0-PRERELEASE, or to the RELENG_7_0, RELENG_6_3, RELENG_6_2,
|
|
RELENG_6_1, or RELENG_5_5 security branch dated after the correction
|
|
date.
|
|
|
|
2) To patch your present system:
|
|
|
|
The following patches have been verified to apply to FreeBSD 5.5, 6.1,
|
|
6.2, 6.3, and 7.0 systems.
|
|
|
|
a) Download the relevant patch from the location below, and verify the
|
|
detached PGP signature using your PGP utility.
|
|
|
|
[FreeBSD 6.2, 6.3, and 7.0]
|
|
# fetch http://security.FreeBSD.org/patches/SA-08:03/sendfile.patch
|
|
# fetch http://security.FreeBSD.org/patches/SA-08:03/sendfile.patch.asc
|
|
|
|
[FreeBSD 6.1]
|
|
# fetch http://security.FreeBSD.org/patches/SA-08:03/sendfile61.patch
|
|
# fetch http://security.FreeBSD.org/patches/SA-08:03/sendfile61.patch.asc
|
|
|
|
[FreeBSD 5.5]
|
|
# fetch http://security.FreeBSD.org/patches/SA-08:03/sendfile55.patch
|
|
# fetch http://security.FreeBSD.org/patches/SA-08:03/sendfile55.patch.asc
|
|
|
|
b) Apply the patch.
|
|
|
|
# cd /usr/src
|
|
# patch < /path/to/patch
|
|
|
|
c) Recompile your kernel as described in
|
|
<URL:http://www.FreeBSD.org/handbook/kernelconfig.html> and reboot the
|
|
system.
|
|
|
|
VI. Correction details
|
|
|
|
The following list contains the revision numbers of each file that was
|
|
corrected in FreeBSD.
|
|
|
|
Branch Revision
|
|
Path
|
|
- -------------------------------------------------------------------------
|
|
RELENG_5
|
|
src/sys/kern/kern_descrip.c 1.243.2.11
|
|
RELENG_5_5
|
|
src/UPDATING 1.342.2.35.2.20
|
|
src/sys/conf/newvers.sh 1.62.2.21.2.21
|
|
src/sys/kern/kern_descrip.c 1.243.2.9.2.1
|
|
RELENG_6
|
|
src/sys/kern/kern_descrip.c 1.279.2.16
|
|
src/sys/kern/uipc_syscalls.c 1.221.2.5
|
|
RELENG_6_3
|
|
src/UPDATING 1.416.2.37.2.5
|
|
src/sys/conf/newvers.sh 1.69.2.15.2.4
|
|
src/sys/kern/kern_descrip.c 1.279.2.15.2.1
|
|
src/sys/kern/uipc_syscalls.c 1.221.2.4.4.1
|
|
RELENG_6_2
|
|
src/UPDATING 1.416.2.29.2.15
|
|
src/sys/conf/newvers.sh 1.69.2.13.2.14
|
|
src/sys/kern/kern_descrip.c 1.279.2.9.2.1
|
|
src/sys/kern/uipc_syscalls.c 1.221.2.4.2.1
|
|
RELENG_6_1
|
|
src/UPDATING 1.416.2.22.2.26
|
|
src/sys/conf/newvers.sh 1.69.2.11.2.25
|
|
src/sys/kern/kern_descrip.c 1.279.2.6.2.1
|
|
src/sys/kern/uipc_syscalls.c 1.221.2.1.2.1
|
|
RELENG_7
|
|
src/sys/kern/kern_descrip.c 1.313.2.1
|
|
src/sys/kern/uipc_syscalls.c 1.259.2.2
|
|
RELENG_7_0
|
|
src/UPDATING 1.507.2.3.2.3
|
|
src/sys/kern/kern_descrip.c 1.313.4.1
|
|
src/sys/kern/uipc_syscalls.c 1.259.4.2
|
|
- -------------------------------------------------------------------------
|
|
|
|
VII. References
|
|
|
|
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-0777
|
|
|
|
The latest revision of this advisory is available at
|
|
http://security.FreeBSD.org/advisories/FreeBSD-SA-08:03.sendfile.asc
|
|
-----BEGIN PGP SIGNATURE-----
|
|
Version: GnuPG v1.4.8 (FreeBSD)
|
|
|
|
iD8DBQFHtC0DFdaIBMps37IRAqp8AJ91+flnCIUSvKoFQyXfD1YTnPnuqgCcDiPJ
|
|
SR4X1dNFENsHMq9ROrQhr1c=
|
|
=TX1R
|
|
-----END PGP SIGNATURE-----
|