Headline
CVE-2023-23625: DOS HAMT Decoding Panics
go-unixfs is an implementation of a unix-like filesystem on top of an ipld merkledag. Trying to read malformed HAMT sharded directories can cause panics and virtual memory leaks. If you are reading untrusted user input, an attacker can then trigger a panic. This is caused by bogus fanout parameter in the HAMT directory nodes. Users are advised to upgrade to version 0.4.3 to resolve this issue. Users unable to upgrade should not feed untrusted user data to the decoding functions.
Impact
Trying to read malformed HAMT sharded directories can cause panics and virtual memory leaks.
If you are reading untrusted user input, an attacker can then trigger a panic.
This is caused by bogus fanout parameter in the HAMT directory nodes.
This include checks returned in ipfs/go-bitfield GHSA-2h6c-j3gf-xp9r, as well as limiting the fanout to <= 1024 (to avoid attempts of arbitrary sized allocations).
Patches
- https://github.com/ipfs/go-unixfs-ghsa-q264-w97q-q778/pull/1/commits/dbcc43ec3e2db0d01e8d80c55040bba3cf22cb4b
Workarounds
Do not feed untrusted user data to the decoding functions.
References
- GHSA-2h6c-j3gf-xp9r
Related news
### Impact Trying to read malformed HAMT sharded directories can cause panics and virtual memory leaks. If you are reading untrusted user input, an attacker can then trigger a panic. This is caused by bogus `fanout` parameter in the HAMT directory nodes. This include checks returned in [ipfs/go-bitfield GHSA-2h6c-j3gf-xp9r](https://github.com/ipfs/go-bitfield/security/advisories/GHSA-2h6c-j3gf-xp9r), as well as limiting the `fanout` to `<= 1024` (to avoid attempts of arbitrary sized allocations). ### Patches - https://github.com/ipfs/go-unixfs/commit/467d139a640ecee4f2e74643dafcc58bb3b54175 ### Workarounds Do not feed untrusted user data to the decoding functions. ### References - https://github.com/ipfs/go-bitfield/security/advisories/GHSA-2h6c-j3gf-xp9r