Networkconfiguration
Monthly
Denial of service in dhcpcd through version 10.3.2 allows an adjacent-network attacker to exhaust memory in the daemon by repeatedly sending crafted IPv6 Router Advertisements with zero-lifetime Route Information options. The unfreed allocations in routeinfo_findalloc() accumulate linearly until the daemon crashes, disrupting DHCP client functionality on the affected host. No public exploit identified at time of analysis, but the upstream fix (commit 708b4a5) is available.
Stack out-of-bounds write in dhcpcd (the widely-used DHCP/DHCPv6 client) through version 10.3.2 lets a same-link attacker corrupt client stack memory by replying with a malicious DHCPv6 ADVERTISE. When dhcpcd serializes an oversized RFC6603 OPTION_PD_EXCLUDE body in dhcp6_makemessage(), a one-byte value is written past a fixed 16-byte stack buffer. No public exploit identified at time of analysis; EPSS is low (0.18%, 7th percentile) and the issue is not in CISA KEV, but a vendor fix (commit 2f00c7b) is available.
Heap use-after-free in dhcpcd through version 10.3.2 allows local unprivileged attackers to crash the DHCP client daemon by exploiting a double-free race between READ and HANGUP events on the control socket. When an attacker sends a privileged command such as -x, control_recvdata() frees the client fd_list object while the subsequent HANGUP event delivers the same stale pointer to control_hangup(), triggering memory corruption that results in denial of network service on the affected host. No public exploit code or CISA KEV listing exists at time of analysis; the upstream fix is available as commit 78ea09e.
Stack memory corruption in dhcpcd through 10.3.2 exposes systems running the DHCPv6 client to availability disruption from unauthenticated attackers on the same network link. The one-byte off-by-one overflow in `dhcp6_makemessage()` is triggered by a crafted DHCPv6 ADVERTISE containing an RFC6603 OPTION_PD_EXCLUDE sub-option with an exclude prefix length of /121 through /128, overflowing a 16-byte stack buffer by exactly one byte. No active exploitation has been confirmed (not listed in CISA KEV), and no public exploit code has been identified at time of analysis; however, the upstream fix commit precisely identifies the trigger, making independent exploit development straightforward.
Heap use-after-free in dhcpcd through 10.3.2 enables unauthenticated same-link attackers - acting as or impersonating a DHCPv6 server - to crash the daemon by sending a crafted DHCPv6 RENEW reply exploiting a pointer lifecycle flaw in delegated prefix deprecation. The flaw triggers dhcp6_deprecatedele() to free a delegated child address while an outer TAILQ_FOREACH_SAFE iterator in dhcp6_deprecateaddrs() still retains the freed pointer, causing a use-after-free when TAILQ_REMOVE is subsequently reached. Impact is limited to availability (daemon crash); no public exploit or CISA KEV listing exists at time of analysis, but the adjacent-network attack vector and zero-privilege requirement lower the bar for local segment adversaries.
Denial of service in dhcpcd through version 10.3.2 allows an adjacent-network attacker to exhaust memory in the daemon by repeatedly sending crafted IPv6 Router Advertisements with zero-lifetime Route Information options. The unfreed allocations in routeinfo_findalloc() accumulate linearly until the daemon crashes, disrupting DHCP client functionality on the affected host. No public exploit identified at time of analysis, but the upstream fix (commit 708b4a5) is available.
Stack out-of-bounds write in dhcpcd (the widely-used DHCP/DHCPv6 client) through version 10.3.2 lets a same-link attacker corrupt client stack memory by replying with a malicious DHCPv6 ADVERTISE. When dhcpcd serializes an oversized RFC6603 OPTION_PD_EXCLUDE body in dhcp6_makemessage(), a one-byte value is written past a fixed 16-byte stack buffer. No public exploit identified at time of analysis; EPSS is low (0.18%, 7th percentile) and the issue is not in CISA KEV, but a vendor fix (commit 2f00c7b) is available.
Heap use-after-free in dhcpcd through version 10.3.2 allows local unprivileged attackers to crash the DHCP client daemon by exploiting a double-free race between READ and HANGUP events on the control socket. When an attacker sends a privileged command such as -x, control_recvdata() frees the client fd_list object while the subsequent HANGUP event delivers the same stale pointer to control_hangup(), triggering memory corruption that results in denial of network service on the affected host. No public exploit code or CISA KEV listing exists at time of analysis; the upstream fix is available as commit 78ea09e.
Stack memory corruption in dhcpcd through 10.3.2 exposes systems running the DHCPv6 client to availability disruption from unauthenticated attackers on the same network link. The one-byte off-by-one overflow in `dhcp6_makemessage()` is triggered by a crafted DHCPv6 ADVERTISE containing an RFC6603 OPTION_PD_EXCLUDE sub-option with an exclude prefix length of /121 through /128, overflowing a 16-byte stack buffer by exactly one byte. No active exploitation has been confirmed (not listed in CISA KEV), and no public exploit code has been identified at time of analysis; however, the upstream fix commit precisely identifies the trigger, making independent exploit development straightforward.
Heap use-after-free in dhcpcd through 10.3.2 enables unauthenticated same-link attackers - acting as or impersonating a DHCPv6 server - to crash the daemon by sending a crafted DHCPv6 RENEW reply exploiting a pointer lifecycle flaw in delegated prefix deprecation. The flaw triggers dhcp6_deprecatedele() to free a delegated child address while an outer TAILQ_FOREACH_SAFE iterator in dhcp6_deprecateaddrs() still retains the freed pointer, causing a use-after-free when TAILQ_REMOVE is subsequently reached. Impact is limited to availability (daemon crash); no public exploit or CISA KEV listing exists at time of analysis, but the adjacent-network attack vector and zero-privilege requirement lower the bar for local segment adversaries.