CVE-2022-40735
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.39%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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 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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 2.39% probability · 83th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-400
- Affected
- diffie-hellman key exchange project/diffie-hellman key exchange
- Source
- cve@mitre.org
References
- https://dheatattack.gitlab.io/
- https://gist.github.com/c0r0n3r/9455ddcab985c50fd1912eabf26e058bThird Party Advisory
- https://github.com/mozilla/ssl-config-generator/issues/162Issue Tracking, Third Party Advisory
- https://ieeexplore.ieee.org/document/10374117
- https://link.springer.com/content/pdf/10.1007/3-540-68339-9_29.pdfTechnical Description, Third Party Advisory
- https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-57pt1r5.pdfTechnical Description, Third Party Advisory, US Government Resource
- https://raw.githubusercontent.com/CVEProject/cvelist/9d7fbbcabd3f44cfedc9e8807757d31ece85a2c6/2022/40xxx/CVE-2022-40735.json
- https://www.researchgate.net/profile/Anton-Stiglic-2/publication/2401745_Security_Issues_in_the_Diffie-Hellman_Key_Agreement_Protocol/links/546c144f0cf20dedafd53e7e/Security-Issues-in-the-Diffie-Hellman-Key-Agreement-Protocol.pdfTechnical Description, Third Party Advisory
- https://www.rfc-editor.org/rfc/rfc3526
- https://www.rfc-editor.org/rfc/rfc4419
- https://www.rfc-editor.org/rfc/rfc5114#section-4
- https://www.rfc-editor.org/rfc/rfc7919#section-5.2
- https://dheatattack.gitlab.io/
- https://gist.github.com/c0r0n3r/9455ddcab985c50fd1912eabf26e058bThird Party Advisory
- https://github.com/mozilla/ssl-config-generator/issues/162Issue Tracking, Third Party Advisory
- https://ieeexplore.ieee.org/document/10374117
- https://link.springer.com/content/pdf/10.1007/3-540-68339-9_29.pdfTechnical Description, Third Party Advisory
- https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-57pt1r5.pdfTechnical Description, Third Party Advisory, US Government Resource
- https://raw.githubusercontent.com/CVEProject/cvelist/9d7fbbcabd3f44cfedc9e8807757d31ece85a2c6/2022/40xxx/CVE-2022-40735.json
- https://www.researchgate.net/profile/Anton-Stiglic-2/publication/2401745_Security_Issues_in_the_Diffie-Hellman_Key_Agreement_Protocol/links/546c144f0cf20dedafd53e7e/Security-Issues-in-the-Diffie-Hellman-Key-Agreement-Protocol.pdfTechnical Description, Third Party Advisory
- https://www.rfc-editor.org/rfc/rfc3526
- https://www.rfc-editor.org/rfc/rfc4419
- https://www.rfc-editor.org/rfc/rfc5114#section-4
- https://www.rfc-editor.org/rfc/rfc7919#section-5.2
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.