Deserialization of Untrusted Data in Log4j

Description

In Apache Log4j 2.x before 2.8.2, when using the TCP socket server or UDP socket server to receive serialized log events from another application, a specially crafted binary payload can be sent that, when deserialized, can execute arbitrary code.

Basic information

Type
reviewed
Severity
critical
Advisory on GitHub
Open advisory ↗
Repository advisory
Source code
Browse source ↗
Published (advisory)
2020-01-06 18:43:38 UTC
Updated
2023-02-01 05:02:44 UTC
GitHub reviewed
2019-12-27 22:02:28 UTC
NVD published
2017-04-17

EPSS Score

Score Percentile
94.01% 99.89%

CVSS Scores

Base score Version Severity Vector
9.8 3.0
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.

Identifiers

CWEs

CWE id Name
CWE-502 Deserialization of Untrusted Data

Affected packages (2)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
maven org.apache.logging.log4j:log4j >= 2.0, < 2.8.2 2.8.2
maven org.apache.logging.log4j:log4j-core >= 2.0, < 2.8.2 2.8.2

References

cvelogic Threat Intelligence