CVE-2022-34820

A vulnerability has been identified in SIMATIC CP 1242-7 V2 (All versions < V3.3.46), SIMATIC CP 1243-1 (All versions < V3.3.46), SIMATIC CP 1243-7 LTE EU (All versions < V3.3.46), SIMATIC CP 1243-7 LTE US (All versions < V3.3.46), SIMATIC CP 1243-8 IRC (All versions < V3.3.46), SIMATIC CP 1542SP-1 IRC (All versions >= V2.0 < V2.2.28), SIMATIC CP 1543-1 (All versions < V3.0.22), SIMATIC CP 1543SP-1 (All versions >= V2.0 < V2.2.28), SIPLUS ET 200SP CP 1542SP-1 IRC TX RAIL (All versions >= V2.0 < V2.2.28), SIPLUS ET 200SP CP 1543SP-1 ISEC (All versions >= V2.0 < V2.2.28), SIPLUS ET 200SP CP 1543SP-1 ISEC TX RAIL (All versions >= V2.0 < V2.2.28), SIPLUS NET CP 1242-7 V2 (All versions < V3.3.46), SIPLUS NET CP 1543-1 (All versions < V3.0.22), SIPLUS S7-1200 CP 1243-1 (All versions < V3.3.46), SIPLUS S7-1200 CP 1243-1 RAIL (All versions < V3.3.46). The application does not correctly escape some user provided fields during the authentication process. This could allow an attacker to inject custom commands and execute arbitrary code with elevated privileges.

Weakness

The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.

Affected Software

Extended Description

Command injection vulnerabilities typically occur when:

Many protocols and products have their own custom command language. While OS or shell command strings are frequently discovered and targeted, developers may not realize that these other command languages might also be vulnerable to attacks. Command injection is a common problem with wrapper programs.

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.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/136.html
• https://cwe.mitre.org/data/definitions/15.html
• https://cwe.mitre.org/data/definitions/183.html
• https://cwe.mitre.org/data/definitions/248.html
• https://cwe.mitre.org/data/definitions/40.html
• https://cwe.mitre.org/data/definitions/43.html
• https://cwe.mitre.org/data/definitions/75.html
• https://cwe.mitre.org/data/definitions/76.html

References

• https://cert-portal.siemens.com/productcert/pdf/ssa-517377.pdf
• https://cert-portal.siemens.com/productcert/pdf/ssa-517377.pdf