AzuraCast before 0.23.4 Remote Code Execution via Liquidsoap string interpolation

AzuraCast before 0.23.4 contains a code injection vulnerability in the ConfigWriter::cleanUpString() method that fails to sanitize Liquidsoap string interpolation sequences, allowing authenticated users with Media or Profile permissions to inject arbitrary Liquidsoap code into station configuration. Attackers can inject #{process.run()} expressions into playlist URLs or station metadata fields that execute shell commands as the azuracast user when the station restarts.