The affected version of this crate did not guard against accessing memory beyond the range of its input data. A pointer cast to read the data into a 256-bit register could lead to a segmentation fault when the end plus the 32 bytes (256 bit) read would overlap into the next page during string parsing. This allows an attacker to eventually crash a service. The flaw was corrected by using a padding buffer for the last read from the input. So that we are we never read over the boundary of the input data.

References

• https://nvd.nist.gov/vuln/detail/CVE-2019-15550
• simd-lite/simd-json#27
• https://rustsec.org/advisories/RUSTSEC-2019-0008.html