CVE Vulnerabilities


Out-of-bounds Read

Published: Apr 28, 2019 | Modified: Apr 22, 2022
CVSS 3.x
CVSS 2.x

dhcp.c in dhcpcd before 7.2.1 contains a 1-byte read overflow with DHO_OPTSOVERLOADED.


The product reads data past the end, or before the beginning, of the intended buffer.

Affected Software

Name Vendor Start Version End Version
Dhcpcd Dhcpcd_project * 7.2.1 (excluding)
Dhcpcd5 Ubuntu bionic *
Dhcpcd5 Ubuntu cosmic *
Dhcpcd5 Ubuntu disco *
Dhcpcd5 Ubuntu eoan *
Dhcpcd5 Ubuntu esm-apps/bionic *
Dhcpcd5 Ubuntu esm-apps/focal *
Dhcpcd5 Ubuntu esm-apps/jammy *
Dhcpcd5 Ubuntu esm-apps/xenial *
Dhcpcd5 Ubuntu focal *
Dhcpcd5 Ubuntu groovy *
Dhcpcd5 Ubuntu hirsute *
Dhcpcd5 Ubuntu impish *
Dhcpcd5 Ubuntu jammy *
Dhcpcd5 Ubuntu kinetic *
Dhcpcd5 Ubuntu lunar *
Dhcpcd5 Ubuntu trusty/esm *
Dhcpcd5 Ubuntu upstream *
Dhcpcd5 Ubuntu xenial *

Potential Mitigations

  • Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
  • When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
  • Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
  • To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.