Deserialization in Web2py
CVE-2016-3957
The secure_load function in gluon/utils.py in web2py before 2.14.2 uses pickle.loads to deserialize session information stored in cookies, which might allow remote attackers to execute arbitrary code by leveraging knowledge of encryption_key.
Vulnerability class: Insecure Deserialization
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.049 (91.8th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 92nd percentile — 91.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.049 · newest: 0.049 · change: 0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- devco.re/blog/2017/01/03/web2py-unserialize-code-execution-CVE-2016-3957/ (Technical Description, Exploit, Third Party Advisory)
- github.com/web2py/web2py/blob/R-2.14.1/gluon/utils.py (Third Party Advisory)
- usn.ubuntu.com/4030-1/ (vendor-advisory)
Frequently asked questions
- What is CVE-2016-3957?
- CVE-2016-3957 is a critical-severity vulnerability in Web2py, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2018-02-06.
- How severe is CVE-2016-3957?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2016-3957 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.