dhcp: insecure temporary file use in the dhcpd init script

The configtest function in the Red Hat dhcpd init script for DHCP 3.0.1 in Red Hat Enterprise Linux (RHEL) 3 allows local users to overwrite arbitrary files via a symlink attack on an unspecified temporary file, related to the "dhcpd -t" command.

dhclient: stack overflow leads to arbitrary code execution as root

Stack-based buffer overflow in the script_write_params method in client/dhclient.c in ISC DHCP dhclient 4.1 before 4.1.0p1, 4.0 before 4.0.1p1, 3.1 before 3.1.2p1, 3.0, and 2.0 allows remote DHCP servers to execute arbitrary code via a crafted subnet-mask option.

dhcp: DoS/abort in some configs with client-identifier and hardware address host specifications

dhcpd in ISC DHCP 3.0.4 and 3.1.1, when the dhcp-client-identifier and hardware ethernet configuration settings are both used, allows remote attackers to cause a denial of service (daemon crash) via unspecified requests.

security flaw

Format string vulnerability in the log functions in dhcpd for dhcp 2.x allows remote DNS servers to execute arbitrary code via certain DNS messages, a different vulnerability than CVE-2002-0702.

The supersede_lease function in memory.c in ISC DHCP (dhcpd) server 2.0pl5 allows remote attackers to cause a denial of service (application crash) via a DHCPDISCOVER packet with a 32 byte client-identifier, which causes the packet to be interpreted as a corrupt uid and causes the server to exit with "corrupt lease uid."

ISC DHCP client program dhclient allows remote attackers to execute arbitrary commands via shell metacharacters.

Format string vulnerabilities in the logging routines for dynamic DNS code (print.c) of ISC DHCP daemon (DHCPD) 3 to 3.0.1rc8, with the NSUPDATE option enabled, allow remote malicious DNS servers to execute arbitrary code via format strings in a DNS server response.

security flaw

ISC dhcrelay (dhcp-relay) 3.0rc9 and earlier, and possibly other versions, allows remote attackers to cause a denial of service (packet storm) via a certain BOOTP packet that is forwarded to a broadcast MAC address, causing an infinite loop that is not restricted by a hop count.

Multiple buffer overflows in ISC DHCP Distribution server (dhcpd) 1.0 and 2.0 allow a remote attacker to cause a denial of service (crash) and possibly execute arbitrary commands via long options.

The DHCP daemon (DHCPD) for ISC DHCP 3.0.1rc12 and 3.0.1rc13, when compiled in environments that do not provide the vsnprintf function, uses C include files that define vsnprintf to use the less safe vsprintf function, which can lead to buffer overflow vulnerabilities that enable a denial of service (server crash) and possibly execute arbitrary code.

security flaw

Multiple stack-based buffer overflows in the error handling routines of the minires library, as used in the NSUPDATE capability for ISC DHCPD 3.0 through 3.0.1RC10, allow remote attackers to execute arbitrary code via a DHCP message containing a long hostname.

Buffer overflow in the logging capability for the DHCP daemon (DHCPD) for ISC DHCP 3.0.1rc12 and 3.0.1rc13 allows remote attackers to cause a denial of service (server crash) and possibly execute arbitrary code via multiple hostname options in (1) DISCOVER, (2) OFFER, (3) REQUEST, (4) ACK, or (5) NAK messages, which can generate a long string when writing to a log file.

A malicious client can overflow a reference counter in ISC dhcpd

A malicious client which is allowed to send very large amounts of traffic (billions of packets) to a DHCP server can eventually overflow a 32-bit reference counter, potentially causing dhcpd to crash. Affects ISC DHCP 4.1.0 -> 4.1-ESV-R15, 4.2.0 -> 4.2.8, 4.3.0 -> 4.3.6, 4.4.0.

dhcp: UDP payload length not properly checked

ISC DHCP 4.x before 4.1-ESV-R12-P1, 4.2.x, and 4.3.x before 4.3.3-P1 allows remote attackers to cause a denial of service (application crash) via an invalid length field in a UDP IPv4 packet.

dhcp: unclosed TCP connections to OMAPI or failover ports can cause DoS

ISC DHCP 4.1.x before 4.1-ESV-R13 and 4.2.x and 4.3.x before 4.3.4 does not restrict the number of concurrent TCP sessions, which allows remote attackers to cause a denial of service (INSIST assertion failure or request-processing outage) by establishing many sessions.

dhcpd: use-after-free error leads crash in IPv6 mode when using mismatched BIND libraries

There had existed in one of the ISC BIND libraries a bug in a function that was used by dhcpd when operating in DHCPv6 mode. There was also a bug in dhcpd relating to the use of this function per its documentation, but the bug in the library function prevented this from causing any harm. All releases of dhcpd from ISC contain copies of this, and other, BIND libraries in combinations that have been tested prior to release and are known to not present issues like this. Some third-party packagers of ISC software have modified the dhcpd source, BIND source, or version matchup in ways that create the crash potential. Based on reports available to ISC, the crash probability is large and no analysis has been done on how, or even if, the probability can be manipulated by an attacker. Affects: Builds of dhcpd versions prior to version 4.4.1 when using BIND versions 9.11.2 or later, or BIND versions with specific bug fixes backported to them. ISC does not have access to comprehensive version lists for all repackagings of dhcpd that are vulnerable. In particular, builds from other vendors may also be affected. Operators are advised to consult their vendor documentation.

dhcp: denial of service flaws

The server in ISC DHCP 3.x and 4.x before 4.2.2, 3.1-ESV before 3.1-ESV-R3, and 4.1-ESV before 4.1-ESV-R3 allows remote attackers to cause a denial of service (daemon exit) via a crafted DHCP packet.

dhcp: remote DoS via zero-length client ID

ISC DHCP 4.1 before 4.1.1-P1 and 4.0 before 4.0.2-P1 allows remote attackers to cause a denial of service (server exit) via a zero-length client ID.

dhcp: NULL pointer dereference crash via crafted DHCPv6 packet

ISC DHCP server 4.0 before 4.0.2, 4.1 before 4.1.2, and 4.2 before 4.2.0-P1 allows remote attackers to cause a denial of service (NULL pointer dereference and crash) via a DHCPv6 packet containing a Relay-Forward message without an address in the Relay-Forward link-address field.

dhcp: server hangs with TCP to failover peer port

ISC DHCP server 4.2 before 4.2.0-P2, when configured to use failover partnerships, allows remote attackers to cause a denial of service (communications-interrupted state and DHCP client service loss) by connecting to a port that is only intended for a failover peer, as demonstrated by a Nagios check_tcp process check to TCP port 520.