CVE-2021-45105— Apache Log4j2 does not always protect from infinite recursion in lookup evaluation
Quick assessment
Affected
Apache Software Foundation Apache Log4j2
Exploitation
Public or AI PoC available; prioritize validation
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
Apache Log4j是美国阿帕奇（Apache）基金会的一款基于Java的开源日志记录工具。 Apache Log4j2 2.0-alpha1到2.16.0版本（不包括2.12.3）存在安全漏洞，该漏洞源于自引用查找的不受控递归。攻击者可利用该漏洞在解释精心编制的字符串时导致拒绝服务。此问题已在2.17.0 和 2.12.3中修复。
Possible ATT&CK Techniques 1 AI
T1499 · Endpoint Denial of ServiceAffected Version Matrix 1
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Apache Software Foundation | Apache Log4j2 | log4j-core< 2.17.0 |
affected |
Get alerts for future matching vulnerabilities
Log in to subscribe
I. Basic Information for CVE-2021-45105
Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗
Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.
Vulnerability Title
Apache Log4j2 does not always protect from infinite recursion in lookup evaluation
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
输入验证不恰当
Source: CVE Program / CVE List V5
Vulnerability Title
Apache Log4j 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Apache Log4j是美国阿帕奇（Apache）基金会的一款基于Java的开源日志记录工具。 Apache Log4j2 2.0-alpha1到2.16.0版本（不包括2.12.3）存在安全漏洞，该漏洞源于自引用查找的不受控递归。攻击者可利用该漏洞在解释精心编制的字符串时导致拒绝服务。此问题已在2.17.0 和 2.12.3中修复。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Shenlong Deep Dive — AI Deep Analysis
10-question deep dive: root cause, exploitation, mitigation, urgency. Read summary free, full version requires login.
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| Apache Software Foundation | Apache Log4j2 | log4j-core ~ 2.17.0 | - |
|
II. Public POCs for CVE-2021-45105
| # | POC Description | Source Link | Shenlong Link |
|---|---|---|---|
| 1 | Log4j_dos_CVE-2021-45105 | https://github.com/cckuailong/Log4j_dos_CVE-2021-45105 | POC Details |
| 2 | None | https://github.com/pravin-pp/log4j2-CVE-2021-45105 | POC Details |
| 3 | Replicating CVE-2021-45105 | https://github.com/tejas-nagchandi/CVE-2021-45105 | POC Details |
| 4 | log4j2 dos exploit,CVE-2021-45105 exploit,Denial of Service poc | https://github.com/iAmSOScArEd/log4j2_dos_exploit | POC Details |
| 5 | None | https://github.com/dileepdkumar/https-github.com-pravin-pp-log4j2-CVE-2021-45105 | POC Details |
| 6 | None | https://github.com/dileepdkumar/https-github.com-dileepdkumar-https-github.com-pravin-pp-log4j2-CVE-2021-45105 | POC Details |
| 7 | None | https://github.com/dileepdkumar/https-github.com-dileepdkumar-https-github.com-pravin-pp-log4j2-CVE-2021-45105-v | POC Details |
| 8 | None | https://github.com/dileepdkumar/https-github.com-pravin-pp-log4j2-CVE-2021-45105-1 | POC Details |
| 9 | Discover and remediate Log4Shell vulnerability [CVE-2021-45105] | https://github.com/sakuraji-labs/log4j-remediation | POC Details |
| 10 | Discover and remediate Log4Shell vulnerability [CVE-2021-45105] | https://github.com/name/log4j-remediation | POC Details |
AI-Generated POC
Premium
No public POC found.
Login to generate AI POCIII. Intelligence Information for CVE-2021-45105
请登录查看更多情报信息。
Vendor Advisories for CVE-2021-45105 (10)
-
https://www.oracle.com/security-alerts/cpujan2022.html x_refsource_MISC
-
https://security.netapp.com/advisory/ntap-20211218-0001/ x_refsource_CONFIRM
-
https://cert-portal.siemens.com/productcert/pdf/ssa-501673.pdf x_refsource_CONFIRM
-
https://cert-portal.siemens.com/productcert/pdf/ssa-479842.pdf x_refsource_CONFIRM
-
https://www.zerodayinitiative.com/advisories/ZDI-21-1541/ x_refsource_MISC
-
https://www.oracle.com/security-alerts/cpujul2022.html x_refsource_MISC
-
https://www.oracle.com/security-alerts/cpuapr2022.html x_refsource_MISC
-
-
-
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbd vendor-advisory x_refsource_CISCO
Mailing List Discussions for CVE-2021-45105 (1)
Other References for CVE-2021-45105 (2)
-
https://logging.apache.org/log4j/2.x/security.html x_refsource_MISC
-
https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0032 x_refsource_CONFIRM
IV. Related Vulnerabilities
Same vendor: Apache Software Foundation
-
CVE-2026-102795
Apache Traffic Server: SNI to Host header matching policy is -
CVE-2026-59265
Apache OpenOffice, Apache OpenOffice: Opening a malicious do -
CVE-2026-66054
Apache Thrift: C++ THeaderTransport does not enforce configu -
CVE-2026-61374
Apache Thrift: Java TSaslTransport post-auth data-frame miss -
CVE-2026-63772
Apache Thrift: Unauthenticated single-packet crash of Go Thr
Same weakness: CWE-20
-
CVE-2026-105117
OpenAM before 16.1.3 Email Content Injection via Users REST -
CVE-2026-63569
MTI/A0 DHAgreement does not validate the peer's ephemeral va -
CVE-2026-55094
Taskcluster: Unauthenticated remote code execution in `web-s -
CVE-2026-47547
NVIDIA驱动固件输入验证漏洞致代码执行 -
CVE-2026-47546
NVIDIA驱动固件输入验证漏洞致代码执行
V. Comments for CVE-2021-45105
No comments yet