CVE-2014-4616 — simplejson
MEDIUMCVE-2014-4616 is a medium-severity (CVSS 5.9) vulnerability in simplejson. 1 public exploit reference exists, so weaponization risk is real. A fix is available for simplejson — see the affected versions and patch details below.
simplejson before 2.6.1 vulnerable to array index error
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2014-4616 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
simplejsonReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Array index error in the scanstring function in the _json module in Python 2.7 through 3.5 and simplejson before 2.6.1 allows context-dependent attackers to read arbitrary process memory via a negative index value in the idx argument to the raw_decode function.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | simplejson | all versions | 2.6.1pip install --upgrade 'simplejson==2.6.1' |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for simplejson, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update simplejson to 2.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2014-4616 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2014-4616 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2014-4616. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This issue affects the versions of python as shipped with Red Hat Enterprise Linux 7, the versions of python-simplejson as shipped with Red Hat Enterprise Linux 5 and 6, and the versions of python33-python and python33-python-simplejson as shipped with Red Hat Software Collections. Red Hat Product Security has rated…
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 7 | python-0:2.7.5-34.el7 | RHSA-2015:2101 |
| Red Hat Satellite 6.0 | python-anyjson-0:0.3.3-4.el6sat | RHEA-2014:1175 |
| Red Hat Software Collections for Red Hat Enterprise Linux 6 | python27-0:1.1-17.el6 | RHSA-2015:1064 |
Frequently Asked Questions
Is CVE-2014-4616 in your dependencies?
O3 Security finds CVE-2014-4616 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.