CVE-2021-45105
MediumExploitedApache Log4j2 vulnerable to Improper Input Validation and Uncontrolled Recursion
Published Dec 18, 2021 · Updated Aug 25, 2026 · Also known as DEBIAN-CVE-2021-45105, DSA-5024-1, GHSA-p6xc-xr62-6r2g, ROOT-APP-MAVEN-CVE-2021-45105, TR-21-1033, UBUNTU-CVE-2021-45105, USN-5203-1
Key Facts
Patch immediately- CVE-2021-45105 is a medium-severity vulnerability (CVSS 5.9 v3.1) affecting Log4j (Apache), Cloud Manager (Netapp), Agile Engineering Data Management (Oracle) and 22 more products.
- It is exploited in the wild, listed in Industry KEV feed since Dec 22, 2021 and is known to be used in ransomware campaigns. No public exploit code is known.
- EPSS estimates a 100% probability of exploitation in the next 30 days.
- Fixed versions are available, including Log4j 2.12.3, Log4j 2.3.1, Log4j 2.17.0-1.1.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
5.9
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS (30-day exploit likelihood)
100%
Higher than 99.9% of all scored CVEs
Exploited in the wild
Yes
1 catalog listing, used by ransomware
Public exploit code
None known
Get the full CVE-2021-45105 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
Apache Log4j2 versions 2.0-alpha1 through 2.16.0 (excluding 2.12.3 and 2.3.1) did not protect from uncontrolled recursion from self-referential lookups. This allows an attacker with control over Thread Context Map data to cause a denial of service when a crafted string is interpreted. This issue was fixed in Log4j 2.17.0, 2.12.3, and 2.3.1.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Dec 22, 2021 | n/a | Known |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
247 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Log4jApache | See advisory | 2.3.1 |
| Cloud ManagerNetapp | See advisory | n/a |
| Agile Engineering Data ManagementOracle | 6.2.1.0 | n/a |
| Agile PlmOracle | 9.3.6 | n/a |
| Agile Plm Mcad ConnectorOracle | 3.6 | n/a |
Patched Releases
Log4j
2.12.3, 2.3.1, 2.17.0-1.1, 2.17.0-1.amzn2022.0.1, 2.17.0-4.13.1, 2.17.0-lp152.3.12.1, 2.17.2-1.amzn2022.0.3
Apache Log4j2
2.17.0, 2.12.3-0+deb9u1, 2.12.4-0ubuntu0.1, 2.17.0-0.20.04.1, 2.17.0-1, 2.17.0-1~deb10u1, 2.17.0-1~deb11u1, 2.17.1-0.20.04.1
aws-kinesis-agent
2.0.5-1.amzn2
eap7-log4j
0:2.17.1-1.redhat_00001.1.el7eap, 0:2.17.1-1.redhat_00001.1.el8eap
io.root.org.apache.logging.log4j:log4j-core
2.17.0-root.io.11, 2.17.0-root.io.12, 2.17.0-root.io.8
log4j-javadoc
2.17.0-1.1, 2.17.0-4.13.1, 2.17.0-lp152.3.12.1
log4j-jcl
2.17.0-1.1, 2.17.0-1.amzn2022.0.1, 2.17.0-4.13.1, 2.17.0-lp152.3.12.1, 2.17.2-1.amzn2022.0.3
log4j-slf4j
2.17.0-1.1, 2.17.0-1.amzn2022.0.1, 2.17.0-4.13.1, 2.17.0-lp152.3.12.1, 2.17.2-1.amzn2022.0.3
openshift-logging/elasticsearch6-rhel8:v5.0.11
2
openshift-logging/elasticsearch6-rhel8:v6.8.1
82
openshift4/ose-logging-elasticsearch6:v4.6.0
202112201736.p0.gce7f68c.assembly.stream
oracle communications convergent charging controller
<=12.0.4.0.0
oracle communications diameter signaling router
<=8.5.1.0
oracle communications element manager
9.0
oracle communications network charging and control
<=12.0.4.0.0
oracle communications session report manager
9.0
oracle communications session route manager
9.0
oracle financial services analytical applications infrastructure
<=8.1.1
oracle flexcube universal banking
<=12.4
oracle health sciences information manager
<=3.0.4
oracle healthcare foundation
<=7.3.0.4
oracle hyperion bi\+
11.2.8.0
oracle hyperion data relationship management
11.2.8.0
oracle hyperion infrastructure technology
11.2.8.0
oracle hyperion planning
11.2.8.0
Timeline
Publicly disclosed
Dec 18, 2021
Added to Industry KEV feed
Dec 22, 2021
Last updated
Aug 25, 2026
Weakness Type
- CWE-20 Improper Input Validation
- CWE-674 Uncontrolled Recursion
- CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')
References
- advisoryhttp://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-22096
- advisoryhttp://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-35550
- advisoryhttp://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-35662
- advisoryhttp://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-44228
- advisoryhttp://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-44832
FAQ
Common Questions.
Apache Log4j2 versions 2.0-alpha1 through 2.16.0 (excluding 2.12.3 and 2.3.1) did not protect from uncontrolled recursion from self-referential lookups.
Affected: Log4j (Apache); Cloud Manager (Netapp); Agile Engineering Data Management (Oracle) versions 6.2.1.0, among others. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since Dec 22, 2021 and is known to be used in ransomware campaigns.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including Log4j 2.12.3, Log4j 2.3.1, Log4j 2.17.0-1.1.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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