Improper Input Validation

Summary

Improper Input Validation, Uncontrolled Resource Consumption vulnerability in Apache Commons Compress in TAR parsing. This issue affects Apache Commons Compress versions 1.22-RC1 through 1.23.0. A third party can create a malformed TAR file by manipulating file modification times headers, which when parsed with Apache Commons Compress, will cause a denial of service issue via CPU consumption. In version 1.22-RC1 of Apache Commons Compress, support was added for file modification times with higher precision (issue # COMPRESS-612). The format for the PAX extended headers carrying this data consists of two numbers separated by a period, indicating seconds and subsecond precision (for example “1647221103.5998539”). The impacted fields are “atime”, “ctime”, “mtime” and “LIBARCHIVE.creationtime”. No input validation is performed prior to the parsing of header values. Parsing of these numbers uses the BigDecimal [3] class from the JDK which has a publicly known algorithmic complexity issue when doing operations on large numbers, causing denial of service (issue # JDK-6560193). A third party can manipulate file time headers in a TAR file by placing a number with a very long fraction (300,000 digits) or a number with exponent notation (such as “9e9999999”) within a file modification time header, and the parsing of files with these headers will take hours instead of seconds, leading to a denial of service via exhaustion of CPU resources.