CVE-2024-1681 — flask-cors
MEDIUMCVE-2024-1681 is a medium-severity (CVSS 5.3) CWE-117 vulnerability in flask-cors. A fix is available for flask-cors — see the affected versions and patch details below.
flask-cors vulnerable to log injection when the log level is set to debug
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-1681.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
flask-corsReal-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
corydolphin/flask-cors is vulnerable to log injection when the log level is set to debug. An attacker can inject fake log entries into the log file by sending a specially crafted GET request containing a CRLF sequence in the request path. This vulnerability allows attackers to corrupt log files, potentially covering tracks of other attacks, confusing log post-processing tools, and forging log entries. The issue is due to improper output neutralization for logs.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | flask-cors | all versions | 4.0.1pip install --upgrade 'flask-cors==4.0.1' |
Affected Products
flask-corscorydolphinDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for flask-cors, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update flask-cors to 4.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-1681 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.
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.
Frequently Asked Questions
Is CVE-2024-1681 in your dependencies?
Find it across PyPI, including transitive dependencies.