CVE-2023-22899 — zip4j
MEDIUMCVE-2023-22899 is a medium-severity (CVSS 5.9) CWE-346 vulnerability in net.lingala.zip4j:zip4j. 2 public exploit references exist, so weaponization risk is real. A fix is available for net.lingala.zip4j:zip4j — see the affected versions and patch details below.
Zip4j Origin Validation Error
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.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-22899.
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-2023-22899 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
net.lingala.zip4j:zip4jReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Zip4j through 2.11.2, as used in Threema and other products, does not always check the MAC when decrypting a ZIP archive. This issue has been fixed in version 2.11.3.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | net.lingala.zip4j:zip4j | all versions | 2.11.3net.lingala.zip4j:zip4j:2.11.3 |
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 net.lingala.zip4j:zip4j, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update net.lingala.zip4j:zip4j to 2.11.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-22899 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-2023-22899 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-22899. 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.
| Product | Fixed in | Advisory |
|---|---|---|
| Migration Toolkit for Runtimes 1 on RHEL 8 | org.jboss.windup-windup-parent | RHSA-2023:3814 |
| MTA-6.2-RHEL-9 | mta/mta-operator-bundle:6.2.0-29 | RHSA-2023:4627 |
Frequently Asked Questions
Is CVE-2023-22899 in your dependencies?
O3 Security finds CVE-2023-22899 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.