CVE-2022-26647

A vulnerability has been identified in SCALANCE X200-4P IRT (All versions < V5.5.2), SCALANCE X201-3P IRT (All versions < V5.5.2), SCALANCE X201-3P IRT PRO (All versions < V5.5.2), SCALANCE X202-2IRT (All versions < V5.5.2), SCALANCE X202-2IRT (All versions < V5.5.2), SCALANCE X202-2P IRT (All versions < V5.5.2), SCALANCE X202-2P IRT PRO (All versions < V5.5.2), SCALANCE X204-2 (All versions < V5.2.6), SCALANCE X204-2FM (All versions < V5.2.6), SCALANCE X204-2LD (All versions < V5.2.6), SCALANCE X204-2LD TS (All versions < V5.2.6), SCALANCE X204-2TS (All versions < V5.2.6), SCALANCE X204IRT (All versions < V5.5.2), SCALANCE X204IRT (All versions < V5.5.2), SCALANCE X204IRT PRO (All versions < V5.5.2), SCALANCE X206-1 (All versions < V5.2.6), SCALANCE X206-1LD (All versions < V5.2.6), SCALANCE X208 (All versions < V5.2.6), SCALANCE X208PRO (All versions < V5.2.6), SCALANCE X212-2 (All versions < V5.2.6), SCALANCE X212-2LD (All versions < V5.2.6), SCALANCE X216 (All versions < V5.2.6), SCALANCE X224 (All versions < V5.2.6), SCALANCE XF201-3P IRT (All versions < V5.5.2), SCALANCE XF202-2P IRT (All versions < V5.5.2), SCALANCE XF204 (All versions < V5.2.6), SCALANCE XF204-2 (All versions < V5.2.6), SCALANCE XF204-2BA IRT (All versions < V5.5.2), SCALANCE XF204IRT (All versions < V5.5.2), SCALANCE XF206-1 (All versions < V5.2.6), SCALANCE XF208 (All versions < V5.2.6). The webserver of affected devices calculates session ids and nonces in an insecure manner. This could allow an unauthenticated remote attacker to brute-force session ids and hijack existing sessions.

Weakness

The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.

Affected Software

Potential Mitigations

• Use a well-vetted algorithm that is currently considered to be strong by experts in the field, and select well-tested implementations with adequate length seeds.
• In general, if a pseudo-random number generator is not advertised as being cryptographically secure, then it is probably a statistical PRNG and should not be used in security-sensitive contexts.
• Pseudo-random number generators can produce predictable numbers if the generator is known and the seed can be guessed. A 256-bit seed is a good starting point for producing a “random enough” number.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/112.html
• https://cwe.mitre.org/data/definitions/485.html
• https://cwe.mitre.org/data/definitions/59.html

References

• https://cert-portal.siemens.com/productcert/pdf/ssa-310038.pdf