Cybersecurity professionals consider CVE-2023-42449 an immediate threat requiring urgent mitigation.
Status: Modified
Last updated: 🕗 21 Nov 2024, 08:22 UTC
Originally published on: 🕗 04 Oct 2023, 20:15 UTC
Time between publication and last update: 413 days
CVSS Release: version 3
security-advisories@github.com
Secondary
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
CVE-2023-42449: Hydra is the two-layer scalability solution for Cardano. Prior to version 0.13.0, it is possible for a malicious head initializer to extract one or more PTs for the head they are initializing due to incorrect data validation logic in the head token minting policy which then results in an flawed check for burning the head ST in the `initial` validator. This is possible because it is not checked in `HeadTokens.hs` that the datums of the outputs at the `initial` validator are equal to the real head ID, and it is also not checked in the `off-chain code`. During the `Initial` state of the protocol, if the malicious initializer removes a PT from the Hydra scripts it becomes impossible for any other participant to reclaim any funds they have attempted to commit into the head, as to do so the Abort transaction must burn all the PTs for the head, but they cannot burn the PT which the attacker controls and so cannot satisfy this requirement. That means the initializer can lock the other participants committed funds forever or until they choose to return the PT (ransom). The malicious initializer can also use the PT to spoof that they have committed a particular TxO when progressing the head into the `Open` state. For example, they could say they committed a TxO residing at their address containing 100 ADA, but in fact this 100 ADA was not moved into the head, and thus in order for an other participant to perform the fanout they will be forced to pay the attacker the 100 ADA out of their own funds, as the fanout transaction must pay all the committed TxOs (even though the attacker did not really commit that TxO). They can do this by placing the PT in a UTxO with a well-formed `Commit` datum with whatever contents they like, then use this UTxO in the `collectCom` transaction. There may be other possible ways to abuse having control of a PT. Version 0.13.0 fixes this issue.
The exploitability of CVE-2023-42449 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
CVE-2023-42449 presents an accessible attack vector with minimal effort required. Restricting access controls and implementing security updates are critical to reducing exploitation risks.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2023-42449, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2023-42449, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
The EPSS score estimates the probability that this vulnerability will be exploited in the near future.
EPSS Score: 0.08% (probability of exploit)
EPSS Percentile: 37.33%
(lower percentile = lower relative risk)
This vulnerability is less risky than approximately 62.67% of others.
NVD-CWE-noinfo
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