#dos

Hydra is the layer-two scalability solution for Cardano. Prior to version 0.13.0, not signing and verifying `$\mathsf{cid}$` allows an attacker (which must be a participant of this head) to use a snapshot from an old head instance with the same participants to close the head or contest the state with it. This can lead to an incorrect distribution of value (= value extraction attack; hard, but possible) or prevent the head to finalize because the value available is not consistent with the closed utxo state (= denial of service; easy). A patch is planned for version 0.13.0. As a workaround, rotate keys between heads so not to re-use keys and not result in the same multi-signature participants.

### Impact When the `++api++` traverser is accidentally used multiple times in a url, handling it takes increasingly longer, making the server less responsive. ### Patches Patches will be released in `plone.rest` 2.0.1 and 3.0.1. Series 1.x is not affected. ### Workarounds In your frontend web server (nginx, Apache) you can redirect `/++api++/++api++` to `/++api++`.

Ubuntu Security Notice 6391-2 - USN-6391-1 fixed a vulnerability in CUPS. This update provides the corresponding update for Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. It was discovered that CUPS incorrectly parsed certain Postscript objects. If a user or automated system were tricked into printing a specially crafted document, a remote attacker could use this issue to cause CUPS to crash, resulting in a denial of service, or possibly execute arbitrary code.

Ubuntu Security Notice 6392-1 - It was discovered that libppd incorrectly parsed certain Postscript objects. If a user or automated system were tricked into printing a specially crafted document, a remote attacker could use this issue to cause libppd to crash, resulting in a denial of service, or possibly execute arbitrary code.

Red Hat Security Advisory 2023-5314-01 - OpenShift API for Data Protection enables you to back up and restore application resources, persistent volume data, and internal container images to external backup storage. OADP enables both file system-based and snapshot-based backups for persistent volumes. Issues addressed include a denial of service vulnerability.

Ubuntu Security Notice 6391-1 - It was discovered that CUPS incorrectly parsed certain Postscript objects. If a user or automated system were tricked into printing a specially crafted document, a remote attacker could use this issue to cause CUPS to crash, resulting in a denial of service, or possibly execute arbitrary code.

Ubuntu Security Notice 6390-1 - It was discovered that Bind incorrectly handled certain control channel messages. A remote attacker with access to the control channel could possibly use this issue to cause Bind to crash, resulting in a denial of service. Robert Story discovered that Bind incorrectly handled certain DNS-over-TLS queries. A remote attacker could possibly use this issue to cause Bind to crash, resulting in a denial of service. This issue only affected Ubuntu 22.04 LTS, and Ubuntu 23.04.

plone.rest allows users to use HTTP verbs such as GET, POST, PUT, DELETE, etc. in Plone. Starting in the 2.x branch and prior to versions 2.0.1 and 3.0.1, when the `++api++` traverser is accidentally used multiple times in a url, handling it takes increasingly longer, making the server less responsive. Patches are available in `plone.rest` 2.0.1 and 3.0.1. Series 1.x is not affected. As a workaround, one may redirect `/++api++/++api++` to `/++api++` in one's frontend web server (nginx, Apache).

The Tungstenite crate through 0.20.0 for Rust allows remote attackers to cause a denial of service (minutes of CPU consumption) via an excessive length of an HTTP header in a client handshake. The length affects both how many times a parse is attempted (e.g., thousands of times) and the average amount of data for each parse attempt (e.g., millions of bytes).

The Tungstenite crate through 0.20.0 for Rust allows remote attackers to cause a denial of service (minutes of CPU consumption) via an excessive length of an HTTP header in a client handshake. The length affects both how many times a parse is attempted (e.g., thousands of times) and the average amount of data for each parse attempt (e.g., millions of bytes).