CVE-2018-5733medium

CVE-2018-5733: medium-severity vulnerability in ISC DHCP

A malicious client can overflow a reference counter in ISC dhcpd

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18Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 5.9epss 20%
In short

A malicious DHCP client can send billions of packets to a DHCP server to overflow an internal counter, potentially crashing the server. This requires the attacker to send massive amounts of traffic over an extended period.

Technical detail

A 32-bit reference counter in ISC dhcpd can be overflowed by a malicious client with network access to the DHCP server, requiring transmission of billions of crafted packets. The overflow can lead to denial of service through server crash. Affected versions: 4.1.0–4.1-ESV-R15, 4.2.0–4.2.8, 4.3.0–4.3.6, 4.4.0.

Summary generated and translated by AI from the official description.
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.
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
ISC · ISC DHCP
Related CVEs — ISC DHCP

In the same product, most dangerous first.

CVE-2017-3144MEDIUMFailure to properly clean up closed OMAPI connections can exhaust available socketsEPSS 72.7%CVE-2021-25217HIGHA buffer overrun in lease file parsing code can be used to exploit a common vulnerability shared by dhcpd and dhclientEPSS 6.1%CVE-2018-5732HIGHA specially constructed response from a malicious server can cause a buffer overflow in dhclientEPSS 5.2%CVE-2022-2928MEDIUMAn option refcount overflow exists in dhcpdEPSS 0.7%CVE-2022-2929MEDIUMDHCP memory leakEPSS 0.7%