[RHSA-2002:229-10] Updated wget packages fix directory traversal bug From: bugzilla@redhat.com To: redhat-watch-list@redhat.com, redhat-announce-list@redhat.com Date: Tuesday 16.23.00 --------------------------------------------------------------------- Red Hat, Inc. Red Hat Security Advisory Synopsis: Updated wget packages fix directory traversal bug Advisory ID: RHSA-2002:229-10 Issue date: 2002-12-10 Updated on: 2002-12-04 Product: Red Hat Linux Keywords: wget directory traversal ftp client flaw:dot Cross references: Obsoletes: CVE Names: CAN-2002-1344 --------------------------------------------------------------------- 1. Topic: The wget packages shipped with Red Hat Linux 6.2 through 8.0 contain a security bug which, under certain circumstances, can cause local files to be written outside the download directory. 2. Relevant releases/architectures: Red Hat Linux 6.2 - i386 Red Hat Linux 7.0 - i386 Red Hat Linux 7.1 - i386, ia64 Red Hat Linux 7.2 - i386, ia64 Red Hat Linux 7.3 - i386 Red Hat Linux 8.0 - i386 3. Problem description: Versions of wget prior to 1.8.2-4 contain a bug that permits a malicious FTP server to create or overwrite files anywhere on the local file system. FTP clients must check to see if an FTP server's response to the NLST command includes any directory information along with the list of filenames required by the FTP protocol (RFC 959, section 4.1.3). If the FTP client fails to do so, a malicious FTP server can send filenames beginning with '/' or containing '/../' which can be used to direct a vulnerable FTP client to write files (such as .forward, .rhosts, .shost, etc.) that can then be used for later attacks against the client machine. All Red Hat Linux users using wget < 1.8.2-4 should upgrade to the errata packages which are not vulnerable to this issue. Thanks to Steven M. Christey for his work in discovering this issue in current FTP clients and for providing a patched FTP server to verify the new packages. 4. Solution: Before applying this update, make sure all previously released errata relevant to your system have been applied. To update all RPMs for your particular architecture, run: rpm -Fvh [filenames] where [filenames] is a list of the RPMs you wish to upgrade. Only those RPMs which are currently installed will be updated. Those RPMs which are not installed but included in the list will not be updated. Note that you can also use wildcards (*.rpm) if your current directory *only* contains the desired RPMs. Please note that this update is also available via Red Hat Network. Many people find this an easier way to apply updates. To use Red Hat Network, launch the Red Hat Update Agent with the following command: up2date This will start an interactive process that will result in the appropriate RPMs being upgraded on your system. 5. RPMs required: Red Hat Linux 6.2: SRPMS: ftp://updates.redhat.com/6.2/en/os/SRPMS/wget-1.8.2-4.6x.src.rpm i386: ftp://updates.redhat.com/6.2/en/os/i386/wget-1.8.2-4.6x.i386.rpm Red Hat Linux 7.0: SRPMS: ftp://updates.redhat.com/7.0/en/os/SRPMS/wget-1.8.2-4.70.src.rpm i386: ftp://updates.redhat.com/7.0/en/os/i386/wget-1.8.2-4.70.i386.rpm Red Hat Linux 7.1: SRPMS: ftp://updates.redhat.com/7.1/en/os/SRPMS/wget-1.8.2-4.71.src.rpm i386: ftp://updates.redhat.com/7.1/en/os/i386/wget-1.8.2-4.71.i386.rpm ia64: ftp://updates.redhat.com/7.1/en/os/ia64/wget-1.8.2-4.71.ia64.rpm Red Hat Linux 7.2: SRPMS: ftp://updates.redhat.com/7.2/en/os/SRPMS/wget-1.8.2-4.72.src.rpm i386: ftp://updates.redhat.com/7.2/en/os/i386/wget-1.8.2-4.72.i386.rpm ia64: ftp://updates.redhat.com/7.2/en/os/ia64/wget-1.8.2-4.72.ia64.rpm Red Hat Linux 7.3: SRPMS: ftp://updates.redhat.com/7.3/en/os/SRPMS/wget-1.8.2-4.73.src.rpm i386: ftp://updates.redhat.com/7.3/en/os/i386/wget-1.8.2-4.73.i386.rpm Red Hat Linux 8.0: SRPMS: ftp://updates.redhat.com/8.0/en/os/SRPMS/wget-1.8.2-5.src.rpm i386: ftp://updates.redhat.com/8.0/en/os/i386/wget-1.8.2-5.i386.rpm 6. Verification: MD5 sum Package Name -------------------------------------------------------------------------- 2c06b1ab033d70ec287bb9c91a8daa68 6.2/en/os/SRPMS/wget-1.8.2-4.6x.src.rpm fffbaeacd02411c23d011b1000f0ab49 6.2/en/os/i386/wget-1.8.2-4.6x.i386.rpm 8cfc796d3489f3d19d4af589bb73641b 7.0/en/os/SRPMS/wget-1.8.2-4.70.src.rpm 8c8abf8f81f057dbd74098b87fb9b54c 7.0/en/os/i386/wget-1.8.2-4.70.i386.rpm 5e022a0c2f4afe5285a5ed6b8abc0ee8 7.1/en/os/SRPMS/wget-1.8.2-4.71.src.rpm 229949e6fdde7a02f56999b4271bc5b1 7.1/en/os/i386/wget-1.8.2-4.71.i386.rpm e24aba62d9589e0999678f880db6de08 7.1/en/os/ia64/wget-1.8.2-4.71.ia64.rpm eefe85c57b07aa14522ab79a5c2f5607 7.2/en/os/SRPMS/wget-1.8.2-4.72.src.rpm 03ae8545b03f137b72b57dc2b2e91e22 7.2/en/os/i386/wget-1.8.2-4.72.i386.rpm 9f349807fbd8ecc7a2678af45e5d4ad1 7.2/en/os/ia64/wget-1.8.2-4.72.ia64.rpm 554d83dadce4e18f0c601c571d43564e 7.3/en/os/SRPMS/wget-1.8.2-4.73.src.rpm 20deb3f2c37f331e87a473fb1cac3d83 7.3/en/os/i386/wget-1.8.2-4.73.i386.rpm 2ab86f0e4955e8e5dc9bf37a4037bfcf 8.0/en/os/SRPMS/wget-1.8.2-5.src.rpm efbebb343ded09fc553e5a34c75697f0 8.0/en/os/i386/wget-1.8.2-5.i386.rpm These packages are GPG signed by Red Hat, Inc. for security. Our key is available at http://www.redhat.com/about/contact/pgpkey.html You can verify each package with the following command: rpm --checksig -v <filename> If you only wish to verify that each package has not been corrupted or tampered with, examine only the md5sum with the following command: md5sum <filename> 7. References: http://marc.theaimsgroup.com/?l=bugtraq&m=87602746719482 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2002-1344 8. Contact: The Red Hat security contact is <security@redhat.com>. More contact details at http://www.redhat.com/solutions/security/news/contact.html Copyright(c) 2000, 2001, 2002 Red Hat, Inc.
RedHat's patch: diff -urN wget-1.8.2/src/fnmatch.c wget-1.8.2_save/src/fnmatch.c --- wget-1.8.2/src/fnmatch.c Sat May 18 05:05:15 2002 +++ wget-1.8.2_save/src/fnmatch.c Fri Oct 4 14:53:40 2002 @@ -198,6 +198,17 @@ return (FNM_NOMATCH); } +/* Return non-zero if S has a leading '/' or contains '../' */ +int +has_invalid_name (const char *s) +{ + if (*s == '/') + return 1; + if (strstr(s, "../") != 0) + return 1; + return 0; +} + /* Return non-zero if S contains globbing wildcards (`*', `?', `[' or `]'). */ int diff -urN wget-1.8.2/src/ftp.c wget-1.8.2_save/src/ftp.c --- wget-1.8.2/src/ftp.c Sat May 18 05:05:16 2002 +++ wget-1.8.2_save/src/ftp.c Fri Oct 4 15:07:22 2002 @@ -1551,6 +1551,8 @@ { struct fileinfo *orig, *start; uerr_t res; + struct fileinfo *f; + con->cmd |= LEAVE_PENDING; @@ -1562,8 +1564,7 @@ opt.accepts and opt.rejects. */ if (opt.accepts || opt.rejects) { - struct fileinfo *f = orig; - + f = orig; while (f) { if (f->type != FT_DIRECTORY && !acceptable (f->name)) @@ -1575,6 +1576,18 @@ f = f->next; } } + /* Remove all files with possible harmful names */ + f = orig; + while (f) + { + if (has_invalid_name(f->name)) + { + logprintf (LOG_VERBOSE, _("Rejecting `%s'.\n"), f->name); + f = delelement (f, &start); + } + else + f = f->next; + } /* Now weed out the files that do not match our globbing pattern. If we are dealing with a globbing pattern, that is. */ if (*u->file && (action == GLOBALL || action == GETONE))
GLSA sent.
