CVE-2024-22040

A vulnerability has been identified in Cerberus PRO EN Engineering Tool (All versions), Cerberus PRO EN Fire Panel FC72x IP6 (All versions), Cerberus PRO EN Fire Panel FC72x IP7 (All versions), Cerberus PRO EN Fire Panel FC72x IP8 (All versions < IP8 SR4), Cerberus PRO EN X200 Cloud Distribution IP7 (All versions), Cerberus PRO EN X200 Cloud Distribution IP8 (All versions < V4.3.5618), Cerberus PRO EN X300 Cloud Distribution IP7 (All versions), Cerberus PRO EN X300 Cloud Distribution IP8 (All versions < V4.3.5617), Cerberus PRO UL Compact Panel FC922/924 (All versions < MP4), Cerberus PRO UL Engineering Tool (All versions < MP4), Cerberus PRO UL X300 Cloud Distribution (All versions < V4.3.0001), Desigo Fire Safety UL Compact Panel FC2025/2050 (All versions < MP4), Desigo Fire Safety UL Engineering Tool (All versions < MP4), Desigo Fire Safety UL X300 Cloud Distribution (All versions < V4.3.0001), Sinteso FS20 EN Engineering Tool (All versions), Sinteso FS20 EN Fire Panel FC20 MP6 (All versions), Sinteso FS20 EN Fire Panel FC20 MP7 (All versions), Sinteso FS20 EN Fire Panel FC20 MP8 (All versions < MP8 SR4), Sinteso FS20 EN X200 Cloud Distribution MP7 (All versions), Sinteso FS20 EN X200 Cloud Distribution MP8 (All versions < V4.3.5618), Sinteso FS20 EN X300 Cloud Distribution MP7 (All versions), Sinteso FS20 EN X300 Cloud Distribution MP8 (All versions < V4.3.5617), Sinteso Mobile (All versions). The network communication library in affected systems insufficiently validates HMAC values which might result in a buffer overread. This could allow an unauthenticated remote attacker to crash the network service.

Weakness

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

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.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/540.html

References

• https://cert-portal.siemens.com/productcert/html/ssa-225840.html
• https://cert-portal.siemens.com/productcert/html/ssa-953710.html