CVE-2016-20013
sha256crypt and sha512crypt through 0.6 allow attackers to cause a denial of service (CPU...
7.5 HighFix available
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
2.17%Up 1.3 points since Feb 19, 2022
What each source reports
NVD Score used
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.
- Record
CVE-2016-20013- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-770
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2016-20013- Updated
- 2026-11-02
EUVDEUVD-2016-3101 No score
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.
- Record
EUVD-2016-3101- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-7rf5-g36v-wpjh No score
sha256crypt and sha512crypt through 0.6 allow attackers to cause a denial of service (CPU...
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.
- Record
GHSA-7rf5-g36v-wpjh- Weakness
- CWE-770
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2016-20013
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.
- Record
UBUNTU-CVE-2016-20013- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVROOT-OS-UBUNTU-2204-CVE-2016-20013 No score
CVE-2016-20013 in glibc - Patched by Root
Root has patched CVE-2016-20013 in the glibc package for Root:Ubuntu:22.04. Multiple fixed versions available.
- Record
ROOT-OS-UBUNTU-2204-CVE-2016-20013- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
glibcRoot:Ubuntu:22.04 |
before 2.35-0ubuntu3.15.aikido.5 | 2.35-0ubuntu3.15.aikido.5 |
rootio-glibcRoot:Ubuntu:22.04 |
before 2.35-0ubuntu3.15.aikido.5 | 2.35-0ubuntu3.15.aikido.5 |
eglibcUbuntu:Pro:14.04:LTS |
All versions, plus listed versions 2.17-93ubuntu42.18-0ubuntu12.18-0ubuntu22.18-0ubuntu42.18-0ubuntu5 Show 24 moreShow less2.18-0ubuntu62.18-0ubuntu72.19-0ubuntu22.19-0ubuntu32.19-0ubuntu42.19-0ubuntu52.19-0ubuntu62.19-0ubuntu6.12.19-0ubuntu6.32.19-0ubuntu6.42.19-0ubuntu6.52.19-0ubuntu6.62.19-0ubuntu6.72.19-0ubuntu6.82.19-0ubuntu6.92.19-0ubuntu6.102.19-0ubuntu6.112.19-0ubuntu6.132.19-0ubuntu6.142.19-0ubuntu6.152.19-0ubuntu6.15+esm12.19-0ubuntu6.15+esm22.19-0ubuntu6.15+esm32.19-0ubuntu6.15+esm4 |
None known |
syslinuxUbuntu:14.04:LTS |
All versions, plus listed versions 3:4.05+dfsg-6+deb7u3ubuntu13:4.05+dfsg-6+deb8u1 |
None known |
zabbixUbuntu:Pro:14.04:LTS |
All versions, plus listed versions 1:2.0.6+dfsg-1ubuntu21:2.2.0+dfsg-1ubuntu11:2.2.0+dfsg-6ubuntu11:2.2.1+dfsg-1ubuntu31:2.2.2+dfsg-1ubuntu1 Show 4 moreShow less1:2.2.2+dfsg-1ubuntu1+esm11:2.2.2+dfsg-1ubuntu1+esm31:2.2.2+dfsg-1ubuntu1+esm41:2.2.2+dfsg-1ubuntu1+esm5 |
None known |
glibcUbuntu:Pro:16.04:LTS |
All versions, plus listed versions 2.21-0ubuntu42.21-0ubuntu52.21-0ubuntu62.23-0ubuntu12.23-0ubuntu2 Show 18 moreShow less2.23-0ubuntu32.23-0ubuntu42.23-0ubuntu52.23-0ubuntu62.23-0ubuntu72.23-0ubuntu92.23-0ubuntu102.23-0ubuntu112.23-0ubuntu11.22.23-0ubuntu11.32.23-0ubuntu11.3+esm12.23-0ubuntu11.3+esm22.23-0ubuntu11.3+esm32.23-0ubuntu11.3+esm52.23-0ubuntu11.3+esm62.23-0ubuntu11.3+esm72.23-0ubuntu11.3+esm82.23-0ubuntu11.3+esm9 |
None known |
sssdUbuntu:Pro:16.04:LTS |
All versions, plus listed versions 1.12.5-21.13.1-21.13.2-11.13.3-11.13.4-1 Show 15 moreShow less1.13.4-1ubuntu11.13.4-1ubuntu1.11.13.4-1ubuntu1.21.13.4-1ubuntu1.51.13.4-1ubuntu1.61.13.4-1ubuntu1.71.13.4-1ubuntu1.81.13.4-1ubuntu1.91.13.4-1ubuntu1.101.13.4-1ubuntu1.111.13.4-1ubuntu1.121.13.4-1ubuntu1.131.13.4-1ubuntu1.141.13.4-1ubuntu1.151.13.4-1ubuntu1.15+esm1 |
None known |
syslinuxUbuntu:16.04:LTS |
All versions, plus listed versions 3:6.03+dfsg-8ubuntu23:6.03+dfsg-11ubuntu1 |
None known |
syslinux-legacyUbuntu:16.04:LTS |
All versions, plus listed versions 2:3.63+dfsg-2ubuntu8 |
None known |
dietlibcUbuntu:16.04:LTS |
All versions, plus listed versions 0.33~cvs20120325-60.33~cvs20120325-6+deb8u1build0.16.04.1 |
None known |
Show 22 moreShow less
| Package | Affected | Fixed |
|---|---|---|
zabbixUbuntu:Pro:16.04:LTS |
All versions, plus listed versions 1:2.4.6+dfsg-11:2.4.7+dfsg-11:2.4.7+dfsg-21:2.4.7+dfsg-2ubuntu21:2.4.7+dfsg-2ubuntu2.1 Show 4 moreShow less1:2.4.7+dfsg-2ubuntu2.1+esm11:2.4.7+dfsg-2ubuntu2.1+esm21:2.4.7+dfsg-2ubuntu2.1+esm31:2.4.7+dfsg-2ubuntu2.1+esm4 |
None known |
glibcUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 2.26-0ubuntu22.26-0ubuntu2.12.27-0ubuntu22.27-0ubuntu32.27-3ubuntu1 Show 11 moreShow less2.27-3ubuntu1.22.27-3ubuntu1.32.27-3ubuntu1.42.27-3ubuntu1.52.27-3ubuntu1.62.27-3ubuntu1.6+esm12.27-3ubuntu1.6+esm22.27-3ubuntu1.6+esm32.27-3ubuntu1.6+esm42.27-3ubuntu1.6+esm52.27-3ubuntu1.6+esm6 |
None known |
sssdUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 1.15.3-2ubuntu11.15.3-3ubuntu11.16.0-5ubuntu11.16.0-5ubuntu21.16.1-1ubuntu1 Show 9 moreShow less1.16.1-1ubuntu1.11.16.1-1ubuntu1.21.16.1-1ubuntu1.31.16.1-1ubuntu1.41.16.1-1ubuntu1.51.16.1-1ubuntu1.61.16.1-1ubuntu1.71.16.1-1ubuntu1.81.16.1-1ubuntu1.8+esm1 |
None known |
syslinuxUbuntu:18.04:LTS |
All versions, plus listed versions 3:6.03+dfsg-14.13:6.03+dfsg1-2 |
None known |
syslinux-legacyUbuntu:18.04:LTS |
All versions, plus listed versions 2:3.63+dfsg-2ubuntu9 |
None known |
dietlibcUbuntu:18.04:LTS |
All versions, plus listed versions 0.34~cvs20160606-7 |
None known |
zabbixUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 1:3.0.7+dfsg-31:3.0.12+dfsg-11:3.0.12+dfsg-1ubuntu0.1~esm11:3.0.12+dfsg-1ubuntu0.1~esm21:3.0.12+dfsg-1ubuntu0.1~esm31:3.0.12+dfsg-1ubuntu0.1~esm4 |
None known |
glibcUbuntu:Pro:20.04:LTS |
All versions, plus listed versions 2.30-0ubuntu22.30-0ubuntu32.31-0ubuntu52.31-0ubuntu62.31-0ubuntu7 Show 13 moreShow less2.31-0ubuntu92.31-0ubuntu9.12.31-0ubuntu9.22.31-0ubuntu9.32.31-0ubuntu9.72.31-0ubuntu9.92.31-0ubuntu9.122.31-0ubuntu9.142.31-0ubuntu9.152.31-0ubuntu9.162.31-0ubuntu9.172.31-0ubuntu9.182.31-0ubuntu9.18+esm1 |
None known |
sssdUbuntu:Pro:20.04:LTS |
All versions, plus listed versions 2.2.0-4ubuntu12.2.2-12.2.2-1ubuntu12.2.3-1.1ubuntu12.2.3-2 Show 14 moreShow less2.2.3-32.2.3-3ubuntu0.12.2.3-3ubuntu0.22.2.3-3ubuntu0.32.2.3-3ubuntu0.42.2.3-3ubuntu0.62.2.3-3ubuntu0.72.2.3-3ubuntu0.82.2.3-3ubuntu0.92.2.3-3ubuntu0.102.2.3-3ubuntu0.112.2.3-3ubuntu0.122.2.3-3ubuntu0.132.2.3-3ubuntu0.13+esm1 |
None known |
syslinuxUbuntu:20.04:LTS |
All versions, plus listed versions 3:6.04~git20190206.bf6db5b4+dfsg1-13:6.04~git20190206.bf6db5b4+dfsg1-2 |
None known |
syslinux-legacyUbuntu:20.04:LTS |
All versions, plus listed versions 2:3.63+dfsg-2ubuntu9 |
None known |
dietlibcUbuntu:20.04:LTS |
All versions, plus listed versions 0.34~cvs20160606-100.34~cvs20160606-110.34~cvs20160606-12 |
None known |
zabbixUbuntu:Pro:20.04:LTS |
All versions, plus listed versions 1:4.0.4+dfsg-1build21:4.0.4+dfsg-1build31:4.0.11+dfsg-11:4.0.14+dfsg-11:4.0.15+dfsg-1 Show 5 moreShow less1:4.0.16+dfsg-11:4.0.16+dfsg-1build11:4.0.17+dfsg-11:4.0.17+dfsg-1ubuntu0.1~esm11:4.0.17+dfsg-1ubuntu0.1~esm2 |
None known |
dietlibcUbuntu:22.04:LTS |
All versions, plus listed versions 0.34~cvs20160606-12 |
None known |
glibcUbuntu:22.04:LTS |
All versions, plus listed versions 2.34-0ubuntu32.35-0ubuntu12.35-0ubuntu32.35-0ubuntu3.12.35-0ubuntu3.3 Show 12 moreShow less2.35-0ubuntu3.42.35-0ubuntu3.52.35-0ubuntu3.62.35-0ubuntu3.72.35-0ubuntu3.82.35-0ubuntu3.92.35-0ubuntu3.102.35-0ubuntu3.112.35-0ubuntu3.122.35-0ubuntu3.132.35-0ubuntu3.142.35-0ubuntu3.15 |
None known |
sssdUbuntu:22.04:LTS |
All versions, plus listed versions 2.4.1-2ubuntu42.5.2-4ubuntu12.5.2-4ubuntu32.5.2-4ubuntu42.6.1-1ubuntu3 Show 9 moreShow less2.6.3-1ubuntu32.6.3-1ubuntu3.12.6.3-1ubuntu3.22.6.3-1ubuntu3.32.6.3-1ubuntu3.42.6.3-1ubuntu3.52.6.3-1ubuntu3.62.6.3-1ubuntu3.82.6.3-1ubuntu3.9 |
None known |
syslinuxUbuntu:22.04:LTS |
All versions, plus listed versions 3:6.04~git20190206.bf6db5b4+dfsg1-3ubuntu1 |
None known |
zabbixUbuntu:22.04:LTS |
All versions, plus listed versions 1:5.0.8+dfsg-1build11:5.0.14+dfsg-11:5.0.17+dfsg-1 |
None known |
dietlibcUbuntu:24.04:LTS |
All versions, plus listed versions 0.34~cvs20160606-14 |
None known |
glibcUbuntu:24.04:LTS |
All versions, plus listed versions 2.38-1ubuntu62.38-3ubuntu12.39-0ubuntu12.39-0ubuntu22.39-0ubuntu6 Show 10 moreShow less2.39-0ubuntu82.39-0ubuntu8.12.39-0ubuntu8.22.39-0ubuntu8.32.39-0ubuntu8.42.39-0ubuntu8.52.39-0ubuntu8.62.39-0ubuntu8.72.39-0ubuntu8.82.39-0ubuntu8.9 |
None known |
sssdUbuntu:24.04:LTS |
All versions, plus listed versions 2.9.1-2ubuntu22.9.1-2ubuntu32.9.2-1ubuntu22.9.4-1ubuntu12.9.4-1.1ubuntu3 Show 10 moreShow less2.9.4-1.1ubuntu52.9.4-1.1ubuntu62.9.4-1.1ubuntu6.12.9.4-1.1ubuntu6.22.9.4-1.1ubuntu6.32.9.4-1.1ubuntu6.42.9.4-1.1ubuntu6.52.9.4-1.1ubuntu6.62.9.4-1.1ubuntu6.72.9.4-1.1ubuntu6.8 |
None known |
syslinuxUbuntu:24.04:LTS |
All versions, plus listed versions 3:6.04~git20190206.bf6db5b4+dfsg1-3ubuntu23:6.04~git20190206.bf6db5b4+dfsg1-3ubuntu3 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2016-20013 is a high vulnerability (CVSS 7.5) in Sha256crypt Project Sha256crypt, published February 19, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.17%, the 82nd percentile. Fixed in glibc 2.35-0ubuntu3.15.aikido.5.
References
twitter.com/solardiz/status/795601240151457793
pthree.org/2018/05/23/do-not-use-sha256crypt-sha512crypt-theyre-dangerous
akkadia.org/drepper/SHA-crypt.txt
nvd.nist.gov/vuln/detail/CVE-2016-20013
github.com/advisories/GHSA-7rf5-g36v-wpjh
ubuntu.com/security/CVE-2016-20013
cve.org/CVERecord?id=CVE-2016-20013