[XZ] Check size of LZMA2 filter properties and throw error if they are wrong

2026-06-23 14:56:41 +00:00 · 2018-08-15 18:57:21 +03:00
parent 0581c32bd5
commit ea080e13ea
1 changed files with 4 additions and 2 deletions
@@ -41,8 +41,10 @@ struct XZBlock {
                else { throw XZError.wrongFilterID }
            // Only LZMA2 filter is supported.
            if filterID == 0x21 {
-                // First, we need to skip byte with the size of filter's properties
-                _ = try byteReader.multiByteDecode()
+                // First, we need to check if size of LZMA2 filter's properties is equal to 1 as expected.
+                let propertiesSize = try byteReader.multiByteDecode()
+                guard propertiesSize == 1
+                    else { throw LZMA2Error.wrongDictionarySize }
                /// In case of LZMA2 filters property is a dicitonary size.
                let filterPropeties = byteReader.byte()
                let closure = { (dwp: ByteReader) -> Data in