CVE-2006-0743: Log4net Denial of Service Vulnerability

MODERATE
Advisory Identifier: GHSA-f9fr-w54q-772h
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CWE-134
Published
Advisory Summary

CVE-2006-0743 is a MODERATE denial of service vulnerability (CWE-134: Use of Externally-Controlled Format String) affecting Log4net libraries in the NuGet ecosystem. The issue involves apache log4net format string vulnerability causes dos. Remediation is available by upgrading affected packages to version 1.2.10.

CVE-2006-0743 at a Glance

CVE Identifier CVE-2006-0743
GHSA Identifier GHSA-f9fr-w54q-772h
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-134: Use of Externally-Controlled Format String
Affected Product Log4net
Package Ecosystem NuGet
Published Date
Last Updated

How to Fix CVE-2006-0743

To remediate this vulnerability, upgrade all affected Log4net dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

log4net fixed: 1.2.10 
Upgrade log4net to 1.2.10
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for log4net

How to Check if You Are Affected

To determine whether your application is affected by CVE-2006-0743, inspect your project dependencies for Log4net:

inspect dependencies for log4net

Analyze the terminal output to locate any version of Log4net in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.2.10), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-134: Use of Externally-Controlled Format String, where the product uses a function that accepts a format string as an argument, but the format string originates from an external source. In Log4net, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Format string vulnerability in LocalSyslogAppender in Apache log4net 1.2.9 might allow remote attackers to cause a denial of service (memory corruption and termination) via unknown vectors.

CVE-2006-0743 Affected Log4net Versions

1 component(s)
Fixed Versions:
1.2.10
Product / Package Ecosystem Affected Versions Fixed Version
log4net
nuget/log4net
NuGet
< 1.2.10
1.2.10

References

NVD — CVE-2006-0743 NVD
https://nvd.nist.gov/vuln/detail/CVE-2006-0743
Security Fix Commit FIX COMMIT
https://github.com/apache/logging-log4net/commit/ea3faab25fe5f1d4dbda9f5da8dcfa6fc3d9e1b8
exchange.xforce.ibmcloud.com/vulnerabilities/251... WEB
https://exchange.xforce.ibmcloud.com/vulnerabilities/25196
Log4net Source Repository REPOSITORY
https://github.com/apache/logging-log4net
Log4net Security Information SECURITY
https://web.archive.org/web/20070114054835/http://www.novell.com/linux/security/advisories/2006_26_sr.html
web.archive.org/web/20140304060609/... WEB
https://web.archive.org/web/20140304060609/https://issues.apache.org/jira/browse/LOG4NET-67
Log4net Security Information SECURITY
https://web.archive.org/web/20200229022118/http://www.securityfocus.com/bid/17095

Frequently Asked Questions

What is CVE-2006-0743?
CVE-2006-0743 is a security vulnerability in Log4net involving Apache log4net format string vulnerability causes DoS under CWE-134: Use of Externally-Controlled Format String.
Which Log4net versions are affected?
Affected versions include releases prior to 1.2.10 across affected packages: log4net.
What version fixes CVE-2006-0743?
Upgrading to 1.2.10 (or the latest patched release for your respective branch) resolves the vulnerability.
Is log4net affected?
Yes, log4net is affected in releases prior to 1.2.10. Upgrade your dependency to 1.2.10 or later.
What CWE is associated with CVE-2006-0743?
CVE-2006-0743 is classified under CWE-134: Use of Externally-Controlled Format String (The product uses a function that accepts a format string as an argument, but the format string originates from an external source.).
How can I check NuGet dependencies for CVE-2006-0743?
Run the dependency tree command: 'inspect dependencies for log4net'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-f9fr-w54q-772h",
  "modified" : "2024-02-09T22:01:06Z",
  "published" : "2022-05-01T06:42:27Z",
  "aliases" : [ "CVE-2006-0743" ],
  "summary" : "Apache log4net format string vulnerability causes DoS",
  "details" : "Format string vulnerability in LocalSyslogAppender in Apache log4net 1.2.9 might allow remote attackers to cause a denial of service (memory corruption and termination) via unknown vectors.",
  "severity" : [ ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "log4net"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.2.10"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.2.9"
    }
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2006-0743"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/apache/logging-log4net/commit/ea3faab25fe5f1d4dbda9f5da8dcfa6fc3d9e1b8"
  }, {
    "type" : "WEB",
    "url" : "https://exchange.xforce.ibmcloud.com/vulnerabilities/25196"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/apache/logging-log4net"
  }, {
    "type" : "WEB",
    "url" : "https://web.archive.org/web/20070114054835/http://www.novell.com/linux/security/advisories/2006_26_sr.html"
  }, {
    "type" : "WEB",
    "url" : "https://web.archive.org/web/20140304060609/https://issues.apache.org/jira/browse/LOG4NET-67"
  }, {
    "type" : "WEB",
    "url" : "https://web.archive.org/web/20200229022118/http://www.securityfocus.com/bid/17095"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-134" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-02-09T22:01:06Z",
    "nvd_published_at" : "2006-03-09T20:02:00Z"
  }
}