Denial of service (via resource exhaustion) due to improper input validation in third-party identifier endpoint

Impact

Missing input validation of some parameters on the endpoints used to confirm third-party identifiers could cause excessive use of disk space and memory leading to resource exhaustion.

Patches

The issue is fixed by https://github.com/matrix-org/synapse/pull/9855.

Workarounds

There are no known workarounds.

References

n/a

For more information

If you have any questions or comments about this advisory, email us at security@matrix.org.