Impact
A denial of service vulnerability exists in the ASF (WMV/WMA) file type detection parser. When parsing a crafted input where an ASF sub-header has a size field of zero, the parser enters an infinite loop. The payload value becomes negative (-24), causing tokenizer.ignore(payload) to move the read position backwards, so the same sub-header is read repeatedly forever.
Any application that uses file-type to detect the type of untrusted/attacker-controlled input is affected. An attacker can stall the Node.js event loop with a 55-byte payload.
Patches
Fixed in version 21.3.1. Users should upgrade to >= 21.3.1.
Workarounds
Validate or limit the size of input buffers before passing them to file-type, or run file type detection in a worker thread with a timeout.
References
Reporter
crnkovic@lokvica.com
Impact
A denial of service vulnerability exists in the ASF (WMV/WMA) file type detection parser. When parsing a crafted input where an ASF sub-header has a
sizefield of zero, the parser enters an infinite loop. Thepayloadvalue becomes negative (-24), causingtokenizer.ignore(payload)to move the read position backwards, so the same sub-header is read repeatedly forever.Any application that uses
file-typeto detect the type of untrusted/attacker-controlled input is affected. An attacker can stall the Node.js event loop with a 55-byte payload.Patches
Fixed in version 21.3.1. Users should upgrade to >= 21.3.1.
Workarounds
Validate or limit the size of input buffers before passing them to
file-type, or run file type detection in a worker thread with a timeout.References
Reporter
crnkovic@lokvica.com