rand_core: incorrect check on buffer length when seeding RNGs (#764)

crates/rand_core/RUSTSEC-0000-0000.md

@@ -0,0 +1,24 @@
+```toml
+[advisory]
+id = "RUSTSEC-0000-0000"
+package = "rand_core"
+date = "2021-02-12"
+url = "https://github.com/rust-random/rand/pull/1096"
+categories = ["crypto-failure"]
+keywords = []
+
+# Optional: metadata which narrows the scope of what this advisory affects
+[affected.functions]
+"rand_core::le::read_u32_into" = ["< 0.6.2, >= 0.6.0"]
+"rand_core::le::read_u64_into" = ["< 0.6.2, >= 0.6.0"]
+
+[versions]
+patched = [">= 0.6.2"]
+unaffected = ["< 0.6.0"]
+```
+
+# Incorrect check on buffer length when seeding RNGs
+
+Summary: rand_core::le::read_u32_into and read_u64_into have incorrect checks on the source buffer length, allowing the destination buffer to be under-filled.
+
+Implications: some downstream RNGs, including Hc128Rng (but not the more widely used ChaCha*Rng), allow seeding using the SeedableRng::from_seed trait-function with too short keys.