CVE-2019-17571

CVE-2019-17571 is a critical-severity vulnerability in Apache Log4j with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 69% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-502.

Key facts

Description

Included in Log4j 1.2 is a SocketServer class that is vulnerable to deserialization of untrusted data which can be exploited to remotely execute arbitrary code when combined with a deserialization gadget when listening to untrusted network traffic for log data. This affects Log4j versions up to 1.2 up to 1.2.17.

Frequently asked questions

What is CVE-2019-17571?
Included in Log4j 1.2 is a SocketServer class that is vulnerable to deserialization of untrusted data which can be exploited to remotely execute arbitrary code when combined with a deserialization gadget when listening to untrusted network traffic for log data. This affects Log4j versions up to 1.2 up to 1.2.17.
How severe is CVE-2019-17571?
CVE-2019-17571 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2019-17571 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 69% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-17571?
CVE-2019-17571 primarily affects Apache Log4j. In total, 27 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-17571?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2019-17571 published?
CVE-2019-17571 was published on 2019-12-20 and last updated on 2026-06-17.

References

Affected products (27)

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