CVE-2022-40735The Diffie-Hellman Key Agreement Protocol allows use of long exponents that arguably make certain calculations unnecessarily expensive,…
- 7.5HighCVSS base score
- 3.6%Exploitation in 30 daysEPSS · top 11% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By mitre
- 2 months later
· 2 months later
Published
- 21 months later
· 21 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 3.6% · top 11% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
n/a
- affected n/a
References
References12
- https://github.com/mozilla/ssl-config-generator/issues/162 (opens in a new tab)x_transferred
- https://gist.github.com/c0r0n3r/9455ddcab985c50fd1912eabf26e058b (opens in a new tab)x_transferred
- https://link.springer.com/content/pdf/10.1007/3-540-68339-9_29.pdf (opens in a new tab)x_transferred
- 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.pdf (opens in a new tab)x_transferred
- https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-57pt1r5.pdf (opens in a new tab)x_transferred
- https://www.rfc-editor.org/rfc/rfc4419 (opens in a new tab)x_transferred
- https://www.rfc-editor.org/rfc/rfc5114#section-4 (opens in a new tab)x_transferred
- https://www.rfc-editor.org/rfc/rfc7919#section-5.2 (opens in a new tab)x_transferred
- https://raw.githubusercontent.com/CVEProject/cvelist/9d7fbbcabd3f44cfedc9e8807757d31ece85a2c6/2022/40xxx/CVE-2022-40735.json (opens in a new tab)x_transferred
- https://www.rfc-editor.org/rfc/rfc3526 (opens in a new tab)x_transferred
- https://dheatattack.gitlab.io/ (opens in a new tab)x_transferred
- https://ieeexplore.ieee.org/document/10374117 (opens in a new tab)x_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2022-44003 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2022-40735)Record last updated .