CVE-2022-40735
Published: 14 November 2022
Summary
CVE-2022-40735 is a high-severity Uncontrolled Resource Consumption (CWE-400) vulnerability in Diffie-Hellman Key Exchange Project Diffie-Hellman Key Exchange. Its CVSS base score is 7.5 (High).
Operationally, ranked in the top 16.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2022-44003
Vulnerability details
The Diffie-Hellman Key Agreement Protocol allows use of long exponents that arguably make certain calculations unnecessarily expensive, because the 1996 van Oorschot and Wiener paper found that "(appropriately) short exponents" can be used when there are adequate subgroup constraints, and…
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these short exponents can lead to less expensive calculations than for long exponents. This issue is different from CVE-2002-20001 because it is based on an observation about exponent size, rather than an observation about numbers that are not public keys. The specific situations in which calculation expense would constitute a server-side vulnerability depend on the protocol (e.g., TLS, SSH, or IKE) and the DHE implementation details. In general, there might be an availability concern because of server-side resource consumption from DHE modular-exponentiation calculations. Finally, it is possible for an attacker to exploit this vulnerability and CVE-2002-20001 together.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Limiting concurrent sessions directly prevents uncontrolled resource consumption by capping the number of active sessions per user or account.
Analysis identifies uncontrolled resource consumption indicative of denial-of-service or abuse attempts.
Contingency plan testing includes resource exhaustion scenarios to verify recovery, making it harder for attackers to sustain exploits that cause uncontrolled consumption.
Updated contingency plans include current procedures to detect, contain, and recover from resource exhaustion, limiting an attacker's ability to sustain impact from uncontrolled consumption.
Alternate site allows resumption of operations if resource exhaustion at the primary site is exploited to cause unavailability.
Alternate telecommunications services enable resumption of essential functions when primary services become unavailable due to uncontrolled resource consumption.
The team can analyze and respond to resource exhaustion incidents, reducing the impact of attacks that exploit uncontrolled consumption weaknesses.
Timely maintenance support and spare parts enable rapid recovery from failures induced by uncontrolled resource consumption, shortening the impact window of denial-of-service attacks.