Skip to content

DragonFly has weak integrity checks for downloaded files

Moderate severity GitHub Reviewed Published Sep 17, 2025 in dragonflyoss/dragonfly • Updated Sep 18, 2025

Package

gomod github.com/dragonflyoss/dragonfly (Go)

Affected versions

< 2.1.0

Patched versions

2.1.0

Description

Impact

The DragonFly2 uses a variety of hash functions, including the MD5 hash. This algorithm does not provide collision resistance; it is secure only against preimage attacks. While these security guarantees may be enough for the DragonFly2 system, it is not completely clear if there are any scenarios where lack of the collision resistance would compromise the system. There are no clear benefits to keeping the MD5 hash function in the system.

var pieceDigests []string
for i := int32(0); i < t.TotalPieces; i++ {
       pieceDigests = append(pieceDigests, t.Pieces[i].Md5)
}
digest := digest.SHA256FromStrings(pieceDigests...)
if digest != t.PieceMd5Sign {
       t.Errorf("invalid digest, desired: %s, actual: %s", t.PieceMd5Sign, digest)
       t.invalid.Store(true)
       return ErrInvalidDigest
}

Alice, a peer in the DragonFly2 system, creates two images: an innocent one, and one with malicious code. Both images consist of two pieces, and Alice generates the pieces so that their respective MD5 hashes collide (are the same). Therefore, the PieceMd5Sign metadata of both images are equal. Alice shares the innocent image with other peers, who attest to their validity (i.e., that it works as expected and is not malicious). Bob wants to download the image and requests it from the peer-to-peer network. After downloading the image, Bob checks its integrity with a SHA256 hash that is known to him. Alice, who is participating in the network, had already provided Bob the other image, the malicious one. Bob unintentionally uses the malicious image.

Patches

  • Dragonfy v2.1.0 and above.

Workarounds

There are no effective workarounds, beyond upgrading.

References

A third party security audit was performed by Trail of Bits, you can see the full report.

If you have any questions or comments about this advisory, please email us at [email protected].

References

@gaius-qi gaius-qi published to dragonflyoss/dragonfly Sep 17, 2025
Published to the GitHub Advisory Database Sep 17, 2025
Reviewed Sep 17, 2025
Published by the National Vulnerability Database Sep 17, 2025
Last updated Sep 18, 2025

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements None
Privileges Required None
User interaction None
Vulnerable System Impact Metrics
Confidentiality None
Integrity Low
Availability None
Subsequent System Impact Metrics
Confidentiality None
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(2nd percentile)

Weaknesses

Use of Weak Hash

The product uses an algorithm that produces a digest (output value) that does not meet security expectations for a hash function that allows an adversary to reasonably determine the original input (preimage attack), find another input that can produce the same hash (2nd preimage attack), or find multiple inputs that evaluate to the same hash (birthday attack). Learn more on MITRE.

CVE ID

CVE-2025-59354

GHSA ID

GHSA-hx2h-vjw2-8r54

Source code

Credits

Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.