module: std
package: encoding/binary
versions:
- fixed: go1.13.15
- fixed: go1.14.7
description: |
  Certain invalid inputs to ReadUvarint or ReadVarint could cause those
  functions to read an unlimited number of bytes from the ByteReader argument
  before returning an error. This could lead to processing more input than
  expected when the caller is reading directly from a network and depends on
  ReadUvarint and ReadVarint only consuming a small, bounded number of bytes,
  even from invalid inputs.

  With the update, ReadUvarint and ReadVarint now always return after consuming
  a bounded number of bytes (specifically, MaxVarintLen64, which is 10). The
  result being returned has not changed; the functions merely detect and return
  some errors without reading as much input.
cves:
- CVE-2020-16845
credit: Diederik Loerakker, Jonny Rhea, Raúl Kripalani, and Preston Van Loon
symbols:
- ReadUvarint
links:
  pr: https://go.dev/cl/247120
  commit: https://go.googlesource.com/go/+/027d7241ce050d197e7fabea3d541ffbe3487258
  context:
  - https://go.dev/issue/40618
  - https://groups.google.com/g/golang-announce/c/NyPIaucMgXo