CVE-2016-3953 json
web2py remote code execution via hardcoded encryption key in session.connect function
published 2018-02-06 8 y ago modified 2026-07-01 4 mo ago also GHSA-q2rq-qgcf-m22w , PYSEC-2026-570 , EUVD-2022-4863
- cvss
- 9.8
- version 3.0, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 3.3%
- EPSS 3.3% chance of exploitation in 30 days, percentile 88%
- public exploits
- 0
- none known
Summary
The sample web application in web2py before 2.14.2 might allow remote attackers to execute arbitrary code via vectors involving use of a hardcoded encryption key when calling the session.connect function.
Patch / fix
- pypi web2py 2.14.2
- web2py web2py 2.14.2
- web2py Ubuntu 16.04 LTS 2.12.3-1ubuntu0.1
ubuntu advisories UBUNTU-CVE-2016-3953
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
Exploit prediction
3.34% chance of exploitation in the next 30 days, higher than 88% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- devco.re https://devco.re/blog/2017/01/03/web2py-unserialize-code-execution-CVE-2016-3957/ referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.0 | 9.8 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P |
| OSV | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| GitHub | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | web2py | <2.14.2 |
2.14.2 |
Classification
- Weakness
-
- CWE-798 Use of Hard-coded Credentials
References
-
github.com
/web2py/web2py/commit/9706d125b42481178d2b423de245f5d2faadbf40
web
-
devco.re
/blog/2017/01/03/web2py-unserialize-code-execution-CVE-2016-3957/
exploit, technical-description, third-party-advisory
-
usn.ubuntu.com
/4030-1/
vendor-advisory
-
github.com
/web2py/web2py/blob/R-2.14.1/applications/examples/models/session.py
web, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2016-3953
advisory
-
github.com
/web2py/web2py/issues/1205
web
-
devco.re
/blog/2017/01/03/web2py-unserialize-code-execution-CVE-2016-3957
web
-
github.com
/web2py/web2py
package
-
usn.ubuntu.com
/4030-1
web
-
pypi.org
/project/web2py
package
-
github.com
/advisories/GHSA-q2rq-qgcf-m22w
advisory
Sources
- CVE List CVE-2016-3953
- GitHub Advisory GHSA-q2rq-qgcf-m22w
- NVD CVE-2016-3953
- OSV PYSEC-2026-570
Fencer Vulns 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.