ISC DHCP 4.1.2 through 4.2.4 and 4.1-ESV before 4.1-ESV-R6 allows remote attackers to cause a denial of service (infinite loop and CPU consumption) via a malformed client identifier.

The remote OracleVM system is missing necessary patches to address critical security updates :

  - exit(2) after sending DHCPDECLINE when dhclient has been     started with '-1' (RHBZ #756490)

  - An error in the handling of malformed client identifiers     can cause a denial-of-service condition in affected     servers. (CVE-2012-3571, #843125)

  - Propagate libdhcp timeout to internal timeout_arg (RHBZ     #736515)

  - A pair of defects cause the server to halt upon     processing certain packets (CVE-2011-2748,     CVE-2011-2749, #729881)

  - dhclient.conf(5), dhclient(8) mention that interface-mtu     option is also requested by default (RHBZ #694264)

  - Better fix for CVE-2011-0997: making domain-name check     more lenient (RHBZ #690577)

  - dhclient requests interface-mtu option by default (RHBZ     #694264)

  - dhclient.conf(5) fix (RHBZ #585855)

  - Make dhcpd init script LSB compliant (RHBZ #610128)

  - Use PID for seeding the random number generator in     dhclient (RHBZ #623953)

  - Add DHCRELAYARGS variable to /etc/sysconfig/dhcrelay     (RHBZ #624965)

  - 'lease imbalance' messages are not logged unless     rebalance was actually attempted (RHBZ #661939)

  - Explicitly clear the ARP cache and flush all addresses &     routes instead of bringing the interface down (RHBZ     #685048)

  - IPoIB support (RHBZ #660679)

  - dhclient: insufficient sanitization of certain DHCP     response values (CVE-2011-0997, #690577)

  - A partner-down failover server no longer emits 'peer     holds all free leases' if it is able to newly-allocate     one of the peer's leases. (RHBZ #610219)

  - The server's 'by client-id' and 'by hardware address'     hash table lists are now sorted according to the     preference to re-allocate that lease to returning     clients. This should eliminate pool starvation problems     arising when 'INIT' clients were given new leases rather     than presently active ones. (RHBZ #615995)

The remote Solaris system is missing necessary patches to address security updates :

  - ISC DHCP 4.1.2 through 4.2.4 and 4.1-ESV before     4.1-ESV-R6 allows remote attackers to cause a denial of     service (infinite loop and CPU consumption) via a     malformed client identifier. (CVE-2012-3571)

  - Multiple memory leaks in ISC DHCP 4.1.x and 4.2.x before     4.2.4-P1 and 4.1-ESV before 4.1-ESV-R6 allow remote     attackers to cause a denial of service (memory     consumption) by sending many requests. (CVE-2012-3954)

This update of dhcp fixed multiple security vulnerabilities (memory leak, Denial of Service).

A denial of service flaw was found in the way the dhcpd daemon handled zero-length client identifiers. A remote attacker could use this flaw to send a specially crafted request to dhcpd, possibly causing it to enter an infinite loop and consume an excessive amount of CPU time.
(CVE-2012-3571)

Two memory leak flaws were found in the dhcpd daemon. A remote attacker could use these flaws to cause dhcpd to exhaust all available memory by sending a large number of DHCP requests. (CVE-2012-3954)

From Red Hat Security Advisory 2012:1141 :

Updated dhcp packages that fix three security issues are now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having moderate security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.

The Dynamic Host Configuration Protocol (DHCP) is a protocol that allows individual devices on an IP network to get their own network configuration information, including an IP address, a subnet mask, and a broadcast address.

A denial of service flaw was found in the way the dhcpd daemon handled zero-length client identifiers. A remote attacker could use this flaw to send a specially crafted request to dhcpd, possibly causing it to enter an infinite loop and consume an excessive amount of CPU time.
(CVE-2012-3571)

Two memory leak flaws were found in the dhcpd daemon. A remote attacker could use these flaws to cause dhcpd to exhaust all available memory by sending a large number of DHCP requests. (CVE-2012-3954)

Upstream acknowledges Markus Hietava of the Codenomicon CROSS project as the original reporter of CVE-2012-3571, and Glen Eustace of Massey University, New Zealand, as the original reporter of CVE-2012-3954.

Users of DHCP should upgrade to these updated packages, which contain backported patches to correct these issues. After installing this update, all DHCP servers will be restarted automatically.

From Red Hat Security Advisory 2012:1140 :

Updated dhcp packages that fix one security issue are now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.

The Dynamic Host Configuration Protocol (DHCP) is a protocol that allows individual devices on an IP network to get their own network configuration information, including an IP address, a subnet mask, and a broadcast address.

A denial of service flaw was found in the way the dhcpd daemon handled zero-length client identifiers. A remote attacker could use this flaw to send a specially crafted request to dhcpd, possibly causing it to enter an infinite loop and consume an excessive amount of CPU time.
(CVE-2012-3571)

Upstream acknowledges Markus Hietava of the Codenomicon CROSS project as the original reporter of this issue.

Users of DHCP should upgrade to these updated packages, which contain a backported patch to correct this issue. After installing this update, all DHCP servers will be restarted automatically.

This update of dhcp fixes two security vulnerabilities :

  - Malformed client identifiers could cause a Denial of     Service (excessive CPU consumption), effectively causing     further client requests to not be processed anymore.
    (CVE-2012-3571)

  - Two unspecified memory leaks. (CVE-2012-3954)     Additionally, the following issues were fixed :

  - The init script of dhcp-server was fixed to check syntax     and fail on force-reload and restart to avoid stopping     of running daemon followed by start failure

  - Added libgcc_s.so to chroot, so the server can report an     assert/crash line.

This update provides dhcp 4.2.4-p1, which fixes the dhcpv6 server crashing while accessing the lease on heap and provides the following additional fixes :

  - Security fixes :

  - Previously the server code was relaxed to allow packets     with zero length client ids to be processed. Under some     situations use of zero length client ids can cause the     server to go into an infinite loop. As such ids are not     valid according to RFC 2132 section 9.14 the server no     longer accepts them. Client ids with a length of 1 are     also invalid but the server still accepts them in order     to minimize disruption. The restriction will likely be     tightened in the future to disallow ids with a length of     1. (ISC-Bugs #29851, CVE-2012-3571)

  - When attempting to convert a DUID from a client id     option into a hardware address handle unexpected client     ids properly. (ISC-Bugs #29852, CVE-2012-3570)

  - A pair of memory leaks were found and fixed. (ISC-Bugs     #30024, (CVE-2012-3954) )

  - Further upstream fixes :

  - Moved lease file check to a separate action so it is not     used in restart -- it can fail when the daemon rewrites     the lease causing a restart failure then.

  - Request dhcp6.sntp-servers in /etc/dhclient6.conf and     forward to netconfig for processing.

  - Rotate the lease file when running in v6 mode. (ISC-Bugs     #24887)

  - Fixed the code that checks if an address the server is     planning to hand out is in a reserved range. This would     appear as the server being out of addresses in pools     with particular ranges. (ISC-Bugs #26498)

  - In the DDNS code handle error conditions more gracefully     and add more logging code. The major change is to handle     unexpected cancel events from the DNS client code.
    (ISC-Bugs #26287)

  - Tidy up the receive calls and eliminate the need for     found_pkt. (ISC-Bugs #25066)

  - Add support for Infiniband over sockets to the server     and relay code.

  - Modify the code that determines if an outstanding DDNS     request should be cancelled. This patch results in     cancelling the outstanding request less often. It fixes     the problem caused by a client doing a release where the     TXT and PTR records weren't removed from the DNS.
    (ISC-BUGS #27858)

  - Remove outdated note in the description of the bootp     keyword about the option not satisfying the requirement     of failover peers for denying dynamic bootp clients.
    (ISC-bugs #28574)

  - Multiple items to clean up IPv6 address processing. When     processing an IA that we've seen check to see if the     addresses are usable (not in use by somebody else)     before handing it out. When reading in leases from the     file discard expired addresses. When picking an address     for a client include the IA ID in addition to the client     ID to generally pick different addresses for different     IAs. (ISC-Bugs #23138, #27945, #25586, #27684)

  - Remove unnecessary checks in the lease query code and     clean up several compiler issues (some dereferences of     NULL and treating an int as a boolean). (ISC-Bugs     #26203)

  - Fix the NA and PD allocation code to handle the case     where a client provides a preference and the server     doesn't have any addresses or prefixes available.
    Previoulsy the server ignored the request with this     patch it replies with a NoAddrsAvail or NoPrefixAvail     response. By default the code performs according to the     errata of August 2010 for RFC 3315 section 17.2.2; to     enable the previous style see the section on     RFC3315_PRE_ERRATA_2010_08 in includes/site.h.

  - Fix up some issues found by static analysis. A potential     memory leak and NULL dereference in omapi. The use of a     boolean test instead of a bitwise test in dst. (ISC-Bugs     #28941)

In addition, the dhcp-server init script now checks the syntax prior restarting the daemon to avoid stopping of the daemon when a start would fail.

The remote host is affected by the vulnerability described in GLSA-201301-06 (ISC DHCP: Denial of Service)

    Multiple vulnerabilities have been discovered in ISC DHCP. Please review       the CVE identifiers referenced below for details.
  Impact :

    The vulnerabilities might allow remote attackers to execute arbitrary       code or cause a Denial of Service.
  Workaround :

    There is no known workaround at this time.

Multiple vulnerabilities has been discovered and corrected in ISC DHCP :

An unexpected client identifier parameter can cause the ISC DHCP daemon to segmentation fault when running in DHCPv6 mode, resulting in a denial of service to further client requests. In order to exploit this condition, an attacker must be able to send requests to the DHCP server (CVE-2012-3570).

An error in the handling of malformed client identifiers can cause a DHCP server running affected versions (see Impact) to enter a state where further client requests are not processed and the server process loops endlessly, consuming all available CPU cycles. Under normal circumstances this condition should not be triggered, but a non-conforming or malicious client could deliberately trigger it in a vulnerable server. In order to exploit this condition an attacker must be able to send requests to the DHCP server (CVE-2012-3571).

Two memory leaks have been found and fixed in ISC DHCP. Both are reproducible when running in DHCPv6 mode (with the -6 command-line argument.) The first leak is confirmed to only affect servers operating in DHCPv6 mode, but based on initial code analysis the second may theoretically affect DHCPv4 servers (though this has not been demonstrated.) (CVE-2012-3954).

The updated packages have been upgraded to the latest version (4.2.4-P1) which is not affected by these issues.

This update of dhcp fixed two security vulnerabilities :

  - Malformed client identifiers could cause a Denial of     Service (excessive CPU consumption), effectively causing     further client requests to not be processed anymore.
    (CVE-2012-3571)

  - Two unspecified memory leaks. (CVE-2012-3954)

This is security bugfix release fixing several vulnerabilities.

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Updated dhcp packages that fix three security issues are now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having moderate security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.

The Dynamic Host Configuration Protocol (DHCP) is a protocol that allows individual devices on an IP network to get their own network configuration information, including an IP address, a subnet mask, and a broadcast address.

A denial of service flaw was found in the way the dhcpd daemon handled zero-length client identifiers. A remote attacker could use this flaw to send a specially crafted request to dhcpd, possibly causing it to enter an infinite loop and consume an excessive amount of CPU time.
(CVE-2012-3571)

Two memory leak flaws were found in the dhcpd daemon. A remote attacker could use these flaws to cause dhcpd to exhaust all available memory by sending a large number of DHCP requests. (CVE-2012-3954)

Upstream acknowledges Markus Hietava of the Codenomicon CROSS project as the original reporter of CVE-2012-3571, and Glen Eustace of Massey University, New Zealand, as the original reporter of CVE-2012-3954.

Users of DHCP should upgrade to these updated packages, which contain backported patches to correct these issues. After installing this update, all DHCP servers will be restarted automatically.

The Dynamic Host Configuration Protocol (DHCP) is a protocol that allows individual devices on an IP network to get their own network configuration information, including an IP address, a subnet mask, and a broadcast address.

A denial of service flaw was found in the way the dhcpd daemon handled zero-length client identifiers. A remote attacker could use this flaw to send a specially crafted request to dhcpd, possibly causing it to enter an infinite loop and consume an excessive amount of CPU time.
(CVE-2012-3571)

Two memory leak flaws were found in the dhcpd daemon. A remote attacker could use these flaws to cause dhcpd to exhaust all available memory by sending a large number of DHCP requests. (CVE-2012-3954)

Users of DHCP should upgrade to these updated packages, which contain backported patches to correct these issues. After installing this update, all DHCP servers will be restarted automatically.

The Dynamic Host Configuration Protocol (DHCP) is a protocol that allows individual devices on an IP network to get their own network configuration information, including an IP address, a subnet mask, and a broadcast address.

A denial of service flaw was found in the way the dhcpd daemon handled zero-length client identifiers. A remote attacker could use this flaw to send a specially crafted request to dhcpd, possibly causing it to enter an infinite loop and consume an excessive amount of CPU time.
(CVE-2012-3571)

Users of DHCP should upgrade to these updated packages, which contain a backported patch to correct this issue. After installing this update, all DHCP servers will be restarted automatically.

The remote Redhat Enterprise Linux 6 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2012:1141 advisory.

  - dhcp: DoS due to error in handling malformed client identifiers (CVE-2012-3571)

  - dhcp: two memory leaks may result in DoS (CVE-2012-3954)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 5 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2012:1140 advisory.

  - dhcp: DoS due to error in handling malformed client identifiers (CVE-2012-3571)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Updated dhcp packages that fix one security issue are now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.

The Dynamic Host Configuration Protocol (DHCP) is a protocol that allows individual devices on an IP network to get their own network configuration information, including an IP address, a subnet mask, and a broadcast address.

A denial of service flaw was found in the way the dhcpd daemon handled zero-length client identifiers. A remote attacker could use this flaw to send a specially crafted request to dhcpd, possibly causing it to enter an infinite loop and consume an excessive amount of CPU time.
(CVE-2012-3571)

Upstream acknowledges Markus Hietava of the Codenomicon CROSS project as the original reporter of this issue.

Users of DHCP should upgrade to these updated packages, which contain a backported patch to correct this issue. After installing this update, all DHCP servers will be restarted automatically.

Several security vulnerabilities affecting ISC dhcpd, a server for automatic IP address assignment, have been discovered. Additionally, the latest security update for isc-dhcp, DSA-2516-1, did not properly apply the patches for CVE-2012-3571 and CVE-2012-3954. This has been addressed in this additional update.

  - CVE-2011-4539     BlueCat Networks discovered that it is possible to crash     DHCP servers configured to evaluate requests with     regular expressions via crafted DHCP request packets.

  - CVE-2012-3571     Markus Hietava of the Codenomicon CROSS project     discovered that it is possible to force the server to     enter an infinite loop via messages with malformed     client identifiers.

  - CVE-2012-3954     Glen Eustace discovered that DHCP servers running in     DHCPv6 mode and possibly DHCPv4 mode suffer of memory     leaks while processing messages. An attacker can use     this flaw to exhaust resources and perform denial of     service attacks.

Two security vulnerabilities affecting ISC dhcpd, a server for automatic IP address assignment, in Debian have been discovered.

  - CVE-2012-3571     Markus Hietava of the Codenomicon CROSS project     discovered that it is possible to force the server to     enter an infinite loop via messages with malformed     client identifiers.

  - CVE-2012-3954     Glen Eustace discovered that DHCP servers running in     DHCPv6 mode and possibly DHCPv4 mode suffer of memory     leaks while processing messages. An attacker can use     this flaw to exhaust resources and perform denial of     service attacks.

Markus Hietava discovered that the DHCP server incorrectly handled certain malformed client identifiers. A remote attacker could use this issue to cause DHCP to crash, resulting in a denial of service.
(CVE-2012-3571)

Glen Eustace discovered that the DHCP server incorrectly handled memory. A remote attacker could use this issue to cause DHCP to crash, resulting in a denial of service. (CVE-2012-3954).

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ISC reports :

An unexpected client identifier parameter can cause the ISC DHCP daemon to segmentation fault when running in DHCPv6 mode, resulting in a denial of service to further client requests. In order to exploit this condition, an attacker must be able to send requests to the DHCP server.

An error in the handling of malformed client identifiers can cause a DHCP server running affected versions (see 'Impact') to enter a state where further client requests are not processed and the server process loops endlessly, consuming all available CPU cycles. Under normal circumstances this condition should not be triggered, but a non-conforming or malicious client could deliberately trigger it in a vulnerable server. In order to exploit this condition an attacker must be able to send requests to the DHCP server.

Two memory leaks have been found and fixed in ISC DHCP. Both are reproducible when running in DHCPv6 mode (with the -6 command-line argument.) The first leak is confirmed to only affect servers operating in DHCPv6 mode, but based on initial code analysis the second may theoretically affect DHCPv4 servers (though this has not been demonstrated.)

ID	Name	Product	Family	Severity
91742	OracleVM 3.2 : dhcp (OVMSA-2016-0058)	Nessus	OracleVM Local Security Checks	high
80647	Oracle Solaris Third-Party Patch Update : isc-dhcp (multiple_denial_of_service_dos4)	Nessus	Solaris Local Security Checks	medium
74718	openSUSE Security Update : dhcp (openSUSE-SU-2012:1006-1)	Nessus	SuSE Local Security Checks	medium
69605	Amazon Linux AMI : dhcp (ALAS-2012-115)	Nessus	Amazon Linux Local Security Checks	medium
68594	Oracle Linux 6 : dhcp (ELSA-2012-1141)	Nessus	Oracle Linux Local Security Checks	medium
68593	Oracle Linux 5 : dhcp (ELSA-2012-1140)	Nessus	Oracle Linux Local Security Checks	medium
64123	SuSE 11.1 Security Update : dhcp (SAT Patch Number 6671)	Nessus	SuSE Local Security Checks	medium
64122	SuSE 11.2 Security Update : dhcp (SAT Patch Number 6606)	Nessus	SuSE Local Security Checks	medium
63440	GLSA-201301-06 : ISC DHCP: Denial of Service	Nessus	Gentoo Local Security Checks	high
61967	Mandriva Linux Security Advisory : dhcp (MDVSA-2012:115)	Nessus	Mandriva Local Security Checks	medium
61595	SuSE 10 Security Update : dhcp (ZYPP Patch Number 8245)	Nessus	SuSE Local Security Checks	medium
61442	Fedora 16 : dhcp-4.2.3-11.P2.fc16 (2012-11110)	Nessus	Fedora Local Security Checks	medium
61437	CentOS 6 : dhcp (CESA-2012:1141)	Nessus	CentOS Local Security Checks	medium
61428	Scientific Linux Security Update : dhcp on SL6.x i386/x86_64 (20120803)	Nessus	Scientific Linux Local Security Checks	medium
61427	Scientific Linux Security Update : dhcp on SL5.x i386/x86_64 (20120803)	Nessus	Scientific Linux Local Security Checks	medium
61405	RHEL 6 : dhcp (RHSA-2012:1141)	Nessus	Red Hat Local Security Checks	high
61404	RHEL 5 : dhcp (RHSA-2012:1140)	Nessus	Red Hat Local Security Checks	high
61400	CentOS 5 : dhcp (CESA-2012:1140)	Nessus	CentOS Local Security Checks	medium
61387	Fedora 17 : dhcp-4.2.4-9.P1.fc17 (2012-11079)	Nessus	Fedora Local Security Checks	medium
61382	Debian DSA-2519-2 : isc-dhcp - several vulnerabilities	Nessus	Debian Local Security Checks	medium
60142	Debian DSA-2516-1 : isc-dhcp - several vulnerabilities	Nessus	Debian Local Security Checks	medium
60137	Ubuntu 11.04 / 11.10 / 12.04 LTS : isc-dhcp vulnerabilities (USN-1519-1)	Nessus	Ubuntu Local Security Checks	medium
60115	FreeBSD : isc-dhcp -- multiple vulnerabilities (c7fa3618-d5ff-11e1-90a2-000c299b62e1)	Nessus	FreeBSD Local Security Checks	medium

Detections

Analytics

CVE-2012-3571

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Tenable Plugins

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