Severity: high


By design, the JDBCAppender in Log4j 1.2.x accepts an SQL statement as a 
configuration parameter where the values to be inserted are converters from 
PatternLayout. The message converter, %m, is likely to always be included. This 
allows attackers to manipulate the SQL by entering crafted strings into input 
fields or headers of an application that are logged allowing unintended SQL 
queries to be executed.

Note this issue only affects Log4j 1.x when specifically configured to use the 
JDBCAppender, which is not the default. Beginning in version 2.0-beta8, the 
JDBCAppender was re-introduced with proper support for parameterized SQL 
queries and further customization over the columns written to in logs.

Apache Log4j 1.2 reached end of life in August 2015. Users should upgrade to 
Log4j 2 as it addresses numerous other issues from the previous versions.


Users should upgrade to Log4j 2 or remove usage of the JDBCAppender from their 


Daniel Martin of NCC Group


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