NanaZip .NET Single-File Parser Integer Underflow Leads to Unbounded Allocation (DoS)

NanaZip is an open source file archive. Starting in version 5.0.1252.0 and prior to versions 6.0.1638.0 and 6.5.1638.0, a denial-of-service vulnerability exists in NanaZip’s `.NET Single File Application` parser. A crafted bundle can force an integer underflow in header-size calculation and trigger an unbounded memory allocation attempt during archive open. Versions 6.0.1638.0 and 6.5.1638.0 fix the issue.