CVE Vulnerabilities

CVE-2021-20606

Out-of-bounds Read

Published: Dec 17, 2021 | Modified: Feb 02, 2023
CVSS 3.x
5.5
MEDIUM
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
CVSS 2.x
4.3 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P
RedHat/V2
RedHat/V3
Ubuntu

Out-of-bounds Read vulnerability in Mitsubishi Electric GX Works2 versions 1.606G and prior, Mitsubishi Electric MELSOFT Navigator versions 2.84N and prior and Mitsubishi Electric EZSocket versions 5.4 and prior allows an attacker to cause a DoS condition in the software by getting a user to open malicious project file specially crafted by an attacker.

Weakness

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

Affected Software

Name Vendor Start Version End Version
Ezsocket Mitsubishielectric * 5.4 (including)
Gx_works2 Mitsubishielectric * 1.606g (including)
Melsoft_navigator Mitsubishielectric * *

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.

References