5.9Medium
Apache Log4j
CVE-2021-45105
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.
What this means for your business
- It affects Apache Log4j. It matters if your company, or a supplier that handles your data, runs it.
- An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 100% chance of attack attempts being seen in the next 30 days, ranking above 99% of all known flaws.
What to do
- 1Check whether your company or your suppliers run Apache Log4j, and which version. The affected versions are listed further down this page.
- 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.
Not sure if your company is exposed?
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Scoring
- CVSS
- 5.9 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H- Weakness
- CWE-20
- Assigned by
- security@apache.org
Dates
- Published
- 2021-12-18
- Last modified
- 2026-08-25
- Sources
- NVD
Affected products
- Apache Log4j2.0 - 2.3.1, 2.4 - 2.12.3, 2.13.0 - 2.16.0
- Netapp Cloud Managerall versions
- Debian Debian Linux10.0, 11.0
- Sonicwall Email Security- 10.0.12
- Sonicwall Network Security Manager2.0 - 3.0
- Sonicwall Web Application Firewall3.0.0 - 3.1.0
- Sonicwall 6bk1602-0aa12-0tp0 Firmware- 2.7.0
- Sonicwall 6bk1602-0aa12-0tp0all versions
- Sonicwall 6bk1602-0aa22-0tp0 Firmware- 2.7.0
- Sonicwall 6bk1602-0aa22-0tp0all versions
- Sonicwall 6bk1602-0aa32-0tp0 Firmware- 2.7.0
- Sonicwall 6bk1602-0aa32-0tp0all versions
As listed in the NVD configuration data. Not a statement about your estate.
References
- http://www.openwall.com/lists/oss-security/2021/12/19/1
- https://cert-portal.siemens.com/productcert/pdf/ssa-479842.pdf
- https://cert-portal.siemens.com/productcert/pdf/ssa-501673.pdf
- https://logging.apache.org/log4j/2.x/security.html
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0032
- https://security.netapp.com/advisory/ntap-20211218-0001/
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbd
- https://www.debian.org/security/2021/dsa-5024
- https://www.kb.cert.org/vuls/id/930724
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://www.oracle.com/security-alerts/cpujul2022.html
- https://www.zerodayinitiative.com/advisories/ZDI-21-1541/
- http://www.openwall.com/lists/oss-security/2021/12/19/1
- https://cert-portal.siemens.com/productcert/pdf/ssa-479842.pdf