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Introduction: IP Spoofing, Part III - ICMP Smurfing
By: Suhas A Desai
"Smurf" is the name of an automated program that attacks a network by exploiting IP broadcast addressing. Smurf and similar programs can cause the attacked part of a network to become "inoperable." Network nodes and their administrators to exchange information about the state of the network use ICMP.
A smurf program builds a network packet with a spoofed victim source address. The packet contains an ICMP ping message addressed to an IP broadcast address, meaning all IP addresses in a given network. If the routing device delivering traffic to those broadcast addresses performs the IP broadcast to layer 2 broadcast function, most hosts on that IP network will reply to it with an ICMP echo reply each. The echo responses to the ping message are sent back to the victim address. Enough pings and resultant echoes can flood the network making it unusable for real traffic.
A related attack is called "fraggle", simple re-write of smurf; uses UDP echo packets in the same fashion as the ICMP echo packets. The intermediary (broadcast) devices, and the spoofed victim are both hurt by this attack. The attackers rely on the ability to source spoofed packets to the "amplifiers" in order to generate the traffic which causes the denial of service.
In order to stop this, all networks should perform filtering either at the edge of the network where customers connect (access layer) or at the edge of the network with connections to the upstream providers, in order to defeat the possibility of source address spoofed packets from entering from downstream networks, or leaving for upstream networks.
One way to defeat smurfing is to disable IP broadcast addressing at each network router since it is seldom used.
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Thank you for reading the LinuxSecurity.com weekly security newsletter. The purpose of this document is to provide our readers with a quick summary of each week's most relevant Linux security headline.
| Debian | ||
| Debian: New proftpd packages fix format string vulnerability | ||
| 1st, September, 2005
Updated package. advisories/debian/debian-new-proftpd-packages-fix-format-string-vulnerability |
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| Debian: New sqwebmail packages fix cross-site scripting | ||
| 1st, September, 2005
Updated package. advisories/debian/debian-new-sqwebmail-packages-fix-cross-site-scripting |
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| Debian: New Mozilla Firefox packages fix several vulnerabilities | ||
| 1st, September, 2005
Update Package. advisories/debian/debian-new-mozilla-firefox-packages-fix-several-vulnerabilities-71271 |
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| Debian: New polygen packages fix denial of service | ||
| 1st, September, 2005
Updated package. advisories/debian/debian-new-polygen-packages-fix-denial-of-service |
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| Debian: New affix packages fix remote command execution | ||
| 1st, September, 2005
Updated package. advisories/debian/debian-new-affix-packages-fix-remote-command-execution |
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| Debian: New zsync packages fix DOS | ||
| 1st, September, 2005
Updated package. advisories/debian/debian-new-zsync-packages-fix-dos |
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| Debian: New phproupware packages fix several vulnerabilities | ||
| 2nd, September, 2005
Updated package. advisories/debian/debian-new-phproupware-packages-fix-several-vulnerabilities |
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| Debian: New webcalendar packages fix remote code execution | ||
| 2nd, September, 2005
Updated package. advisories/debian/debian-new-webcalendar-packages-fix-remote-code-execution |
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| Debian: New pcre3 packages fix arbitrary code execution | ||
| 2nd, September, 2005
Updated package. advisories/debian/debian-new-pcre3-packages-fix-arbitrary-code-execution-86900 |
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| Debian: Updated i386 proftpd packages fix format string vulnerability | ||
| 2nd, September, 2005
Updated package. advisories/debian/debian-updated-i386-proftpd-packages-fix-format-string-vulnerability |
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| Debian: New ntp packages fix group id confusion | ||
| 5th, September, 2005
Updated package. advisories/debian/debian-new-ntp-packages-fix-group-id-confusion |
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| Debian: New cvs packages fix insecure temporary files | ||
| 7th, September, 2005
Updated package. advisories/debian/debian-new-cvs-packages-fix-insecure-temporary-files-45438 |
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| Debian: New Apache packages fix HTTP request smuggling | ||
| 8th, September, 2005
Updated package. advisories/debian/debian-new-apache-packages-fix-http-request-smuggling |
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| Debian: New kdelibs packages fix backup file information leak | ||
| 8th, September, 2005
Updated package. advisories/debian/debian-new-kdelibs-packages-fix-backup-file-information-leak-15398 |
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| Fedora | ||
| Fedora Core 4 Update: evince-0.4.0-1.2 | ||
| 1st, September, 2005
Updated package. advisories/fedora/fedora-core-4-update-evince-040-12-11-23-00-120279 |
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| Fedora Core 4 Update: openmotif-2.2.3-10.FC4.1 | ||
| 2nd, September, 2005
Updated package. advisories/fedora/fedora-core-4-update-openmotif-223-10fc41-12-39-00-120289 |
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| Fedora Core 4 Update: cman-kernel-2.6.11.5-20050601.152643.FC4.12 | ||
| 2nd, September, 2005
Rebuild for latest kernel, 2.6.12-1.1447_FC4. advisories/fedora/fedora-core-4-update-cman-kernel-26115-20050601152643fc412-13-21-00-120290 |
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| Fedora Core 4 Update: gnbd-kernel-2.6.11.2-20050420.133124.FC4.45 | ||
| 2nd, September, 2005
Rebuild for latest kernel, 2.6.12-1.1447_FC4. advisories/fedora/fedora-core-4-update-gnbd-kernel-26112-20050420133124fc445-13-21-00-120291 |
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| Fedora Core 4 Update: dlm-kernel-2.6.11.5-20050601.152643.FC4.12 | ||
| 2nd, September, 2005
Rebuild for latest kernel, 2.6.12-1.1447_FC4. advisories/fedora/fedora-core-4-update-dlm-kernel-26115-20050601152643fc412-13-22-00-120292 |
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| Fedora Core 4 Update: GFS-kernel-2.6.11.8-20050601.152643.FC4.14 | ||
| 2nd, September, 2005
Rebuild for latest kernel, 2.6.12-1.1447_FC4. advisories/fedora/fedora-core-4-update-gfs-kernel-26118-20050601152643fc414-13-23-00-120293 |
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| Fedora Core 4 Update: lockdev-1.0.1-7.1 | ||
| 2nd, September, 2005
Updated package. advisories/fedora/fedora-core-4-update-lockdev-101-71-22-43-00-120295 |
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| Fedora Core 3 Update: perl-Compress-Zlib-1.37-1.fc3 | ||
| 6th, September, 2005
Some bug fixes so the amavis users stop complaining. =) advisories/fedora/fedora-core-3-update-perl-compress-zlib-137-1fc3-01-59-00-120303 |
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| Fedora Core 4 Update: perl-Compress-Zlib-1.37-1.fc4 | ||
| 6th, September, 2005
Some bug fixes so the amavis users stop complaining. =) advisories/fedora/fedora-core-4-update-perl-compress-zlib-137-1fc4-02-00-00-120304 |
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| Fedora Core 3 Update: perl-DBI-1.40-6.fc3 | ||
| 6th, September, 2005
Old and low priority security update that we forgot to push a while ago. advisories/fedora/fedora-core-3-update-perl-dbi-140-6fc3-02-00-00-120305 |
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| Fedora Core 4 Update: termcap-5.4-6 | ||
| 6th, September, 2005
Updated package. advisories/fedora/fedora-core-4-update-termcap-54-6-02-01-00-120306 |
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| Fedora Core 4 Update: ckermit-8.0.211-3.FC4 | ||
| 6th, September, 2005
Updated package. advisories/fedora/fedora-core-4-update-ckermit-80211-3fc4-02-02-00-120307 |
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| Fedora Core 4 Update: kdegraphics-3.4.2-0.fc4.2 | ||
| 6th, September, 2005
Updated package. advisories/fedora/fedora-core-4-update-kdegraphics-342-0fc42-02-02-00-120308 |
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| Fedora Core 4 Update: squid-2.5.STABLE9-8 | ||
| 6th, September, 2005
Updated package. advisories/fedora/fedora-core-4-update-squid-25stable9-8-13-01-00-120315 |
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| Fedora Core 3 Update: squid-2.5.STABLE9-1.FC3.7 | ||
| 6th, September, 2005
Updated package. advisories/fedora/fedora-core-3-update-squid-25stable9-1fc37-13-01-00-120316 |
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| Fedora Core 4 Update: pam-0.79-9.5 | ||
| 6th, September, 2005
This update should fix potential problems with auditing in pam when used on systems with kernels without audit compiled in. advisories/fedora/fedora-core-4-update-pam-079-95-16-35-00-120317 |
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| Fedora Core 4 Update: setup-2.5.44-1.1 | ||
| 6th, September, 2005
Updated package. advisories/fedora/fedora-core-4-update-setup-2544-11-21-35-00-120318 |
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| Fedora Core 4 Update: tar-1.15.1-10.FC4 | ||
| 7th, September, 2005
Updated package. advisories/fedora/fedora-core-4-update-tar-1151-10fc4-13-56-00-120323 |
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| Fedora Core 3 Update: openssh-3.9p1-8.0.3 | ||
| 7th, September, 2005
This security update fixes CAN-2005-2798 and resolves a problem with X forwarding binding only on IPv6 address on certain circumstances. advisories/fedora/fedora-core-3-update-openssh-39p1-803-13-57-00-120324 |
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| Fedora Core 4 Update: tzdata-2005m-1.fc4 | ||
| 7th, September, 2005
Updated package. advisories/fedora/fedora-core-4-update-tzdata-2005m-1fc4-13-57-00-120325 |
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| Fedora Core 3 Update: tzdata-2005m-1.fc3 | ||
| 7th, September, 2005
Updated package. advisories/fedora/fedora-core-3-update-tzdata-2005m-1fc3-13-58-00-120326 |
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| Fedora Core 4 Update: httpd-2.0.54-10.2 | ||
| 7th, September, 2005
This update includes two security fixes. An issue was discovered in mod_ssl where "SSLVerifyClient require" would not be honoured in location context if the virtual host had "SSLVerifyClient optional" configured (CAN-2005-2700). advisories/fedora/fedora-core-4-update-httpd-2054-102-16-57-00-120327 |
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| Fedora Core 3 Update: httpd-2.0.53-3.3 | ||
| 7th, September, 2005
This update includes two security fixes. An issue was discovered in mod_ssl where "SSLVerifyClientrequire" would not be honoured in location context if the virtual host had "SSLVerifyClient optional" configured (CAN-2005-2700). advisories/fedora/fedora-core-3-update-httpd-2053-33-16-57-00-120328 |
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| Gentoo | ||
| Gentoo: MPlayer Heap overflow in ad_pcm.c | ||
| 1st, September, 2005
A heap overflow in MPlayer might lead to the execution of arbitrary code. |
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| Gentoo: Gnumeric Heap overflow in the included PCRE library | ||
| 3rd, September, 2005
Gnumeric is vulnerable to a heap overflow, possibly leading to the execution of arbitrary code. |
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| Gentoo: OpenTTD Format string vulnerabilities | ||
| 5th, September, 2005
OpenTTD is vulnerable to format string vulnerabilities which may result in remote execution of arbitrary code. |
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| Gentoo: phpLDAPadmin Authentication bypass | ||
| 6th, September, 2005
A flaw in phpLDAPadmin may allow attackers to bypass security restrictions and connect anonymously. |
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| Gentoo: Net-SNMP Insecure RPATH | ||
| 6th, September, 2005
The Gentoo Net-SNMP package may provide Perl modules containing an insecure DT_RPATH, potentially allowing privilege escalation. |
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| Gentoo: Squid Denial of Service vulnerabilities | ||
| 7th, September, 2005
Squid contains several bugs when handling certain malformed requests resulting in a Denial of Service. |
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| Red Hat | ||
| RedHat: Important: httpd security update | ||
| 6th, September, 2005
Updated Apache httpd packages that correct two security issues are now available for Red Hat Enterprise Linux 3 and 4. This update has been rated as having important security impact by the Red Hat Security Response Team. advisories/red-hat/redhat-important-httpd-security-update-RHSA-2009-1148-01 |
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| RedHat: Low: cvs security update | ||
| 6th, September, 2005
An updated cvs package that fixes a security bug is now available. This update has been rated as having low security impact by the Red Hat Security Response Team. advisories/red-hat/redhat-low-cvs-security-update-RHSA-2005-756-01 |
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