XML External Entity attack in log4net
Apache log4net before 2.0.10 does not disable XML external entities when parsing log4net configuration files. This could allow for XXE-based attacks in applications that accept arbitrary configuration files from users.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| .NET (NuGet) | log4net | < 2.0.10 | 2.0.10 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2018-1285
- https://www.whitesourcesoftware.com/vulnerability-database/CVE-2018-1285
- https://www.oracle.com/security-alerts/cpujan2021.html
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://www.oracle.com/security-alerts/cpuApr2021.html
- https://www.nuget.org/packages/log4net
- https://snyk.io/vuln/SNYK-DOTNET-LOG4NET-568897
- https://security.netapp.com/advisory/ntap-20220909-0001
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VT2DNNSW7C7FNK3MA3SLEUHGW5USYZKE
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VKL2LPINAI6BCMXOH4V4HVHGLUXIWOFO
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/M2U233HVAQDSZ2PRG4XSGDASLY3J6ALH
- https://lists.apache.org/thread.html/reab1c277c95310bad1038255e0757857b2fbe291411b4fa84552028a%40%3Cdev.logging.apache.org%3E
- https://lists.apache.org/thread.html/rdbac24c945ca5c69cd5348b5ac023bc625768f653335de146e09ae2d@%3Cdev.logging.apache.org%3E
- https://lists.apache.org/thread.html/rd2d72a017e238d1f345f9d14e075c81be16fc68a41c9e9ad9e29a732@%3Cdev.logging.apache.org%3E
- https://lists.apache.org/thread.html/r9de86a185575e6c5f92e2a70a1d2e2e9514dc4341251577aac8e3866@%3Cdev.logging.apache.org%3E
- https://lists.apache.org/thread.html/r7ab6b6e702f11a6f77b0db2af2d5e5532f56ae4b99b5fe73c5200b6a@%3Cdev.logging.apache.org%3E
- https://lists.apache.org/thread.html/r6543acafca3e2d24ff4b0c364a91540cb9378977ffa8d37a03ab4b0f@%3Cdev.logging.apache.org%3E
- https://lists.apache.org/thread.html/r525cbbd7db0aef4a114cf60de8439aa285decc34904d42a7f14f39c3@%3Cdev.logging.apache.org%3E
- https://lists.apache.org/thread.html/r33564de316d4e4ba0fea1d4d079e62cde1ffe64369c1157243d840d9@%3Cdev.logging.apache.org%3E
- https://lists.apache.org/thread.html/r00b16ac5e0bbf7009a0d167ed58f3f94d0033b0f4b3e3d5025cc4872@%3Cdev.logging.apache.org%3E
- https://issues.apache.org/jira/browse/LOG4NET-575
- https://github.com/apache/logging-log4net
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- Weakness (CWE)
CWE-611- Platform
- .NET (NuGet)
- Package
log4net- Disclosed
- 29.01.2021
- Updated
- 11.10.2026 11:23
Sources and licenses
OSV / GitHub Advisory Database - GHSA-2cwj-8chv-9pp9 - CC BY 4.0
Vulnerability history: log4net
All published vulnerabilities of this package (.NET (NuGet)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 3
- First → latest
- 01.2021 04.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 1
- Medium 2
Disclosures per year
- 2021: 1
- 2022: 1
- 2023: 0
- 2024: 0
- 2025: 0
- 2026: 1
-
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