CVE-2016-20013 json
sha256crypt and sha512crypt through 0.6 allow attackers to cause a denial of service (CPU consumption) because the algorithm's runtime is p…
published 2022-02-19 4 y ago modified 2026-06-17 4 mo ago also EUVD-2016-3101
- cvss
- 7.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 2.2%
- EPSS 2.2% chance of exploitation in 30 days, percentile 82%
- public exploits
- 0
- none known
Summary
sha256crypt and sha512crypt through 0.6 allow attackers to cause a denial of service (CPU consumption) because the algorithm's runtime is proportional to the square of the length of the password.
Exploit prediction
2.17% chance of exploitation in the next 30 days, higher than 82% of all scored CVEs (FIRST EPSS, 2026-11-09).
Exploits and checks
- pthree.org https://pthree.org/2018/05/23/do-not-use-sha256crypt-sha512crypt-theyre-dangerous/ referenced PoC, tagged "exploit" by a source, unverified
- akkadia.org https://akkadia.org/drepper/SHA-crypt.txt referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:N/I:N/A:P |
Classification
- Weakness
-
- CWE-770 Allocation of Resources Without Limits or Throttling
References
-
pthree.org
/2018/05/23/do-not-use-sha256crypt-sha512crypt-theyre-dangerous/
exploit, third-party-advisory
-
akkadia.org
/drepper/SHA-crypt.txt
exploit, third-party-advisory
-
twitter.com
/solardiz/status/795601240151457793
third-party-advisory
Sources
- CVE List CVE-2016-20013
- NVD CVE-2016-20013
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.