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gokey allows secret recovery from a seed file without the master password

High severity GitHub Reviewed Published Dec 2, 2025 in cloudflare/gokey • Updated Dec 2, 2025

Package

gomod github.com/cloudflare/gokey (Go)

Affected versions

< 0.2.0

Patched versions

0.2.0

Description

In gokey versions <0.2.0, a flaw in the seed decryption logic resulted in passwords incorrectly being derived solely from the initial vector and the AES-GCM authentication tag of the key seed.

This issue has been fixed in gokey version 0.2.0. This is a breaking change. The fix has invalidated any passwords/secrets that were derived from the seed file (using the -s option). Even if the input seed file stays the same, version 0.2.0 gokey will generate different secrets.

Impact

This vulnerability impacts generated keys/secrets using a seed file as an entropy input (using the -s option). Keys/secrets generated just from the master password (without the -s option) are not impacted. The confidentiality of the seed itself is also not impacted (it is not required to regenerate the seed itself). Specific impact includes:

  • keys/secrets generated from a seed file may have lower entropy: it was expected that the whole seed would be used to generate keys (240 bytes of entropy input), where in vulnerable versions only 28 bytes was used
  • a malicious entity could have recovered all passwords, generated from a particular seed, having only the seed file in possession without the knowledge of the seed master password

Patches

The code logic bug has been fixed in gokey version 0.2.0 and above. Due to the deterministic nature of gokey, fixed versions will produce different passwords/secrets using seed files, as all seed entropy will be used now.

System secret rotation guidance

It is advised for users to regenerate passwords/secrets using the patched version of gokey (0.2.0 and above), and provision/rotate these secrets into respective systems in place of the old secret. A specific rotation procedure is system-dependent, but most common patterns are described below.

Systems that do not require the old password/secret for rotation

Such systems usually have a "Forgot password" facility or a similar facility allowing users to rotate their password/secrets by sending a unique "magic" link to the user's email or phone. In such cases users are advised to use this facility and input the newly generated password secret, when prompted by the system.

Systems that require the old password/secret for rotation

Such systems usually have a modal password rotation window usually in the user settings section requiring the user to input the old and the new password sometimes with a confirmation. To generate/recover the old password in such cases users are advised to:

  • temporarily download gokey version 0.1.3 for their respective operating system to recover the old password
  • use gokey version 0.2.0 or above to generate the new password
  • populate the system provided password rotation form

Systems that allow multiple credentials for the same account to be provisioned

Such systems usually require a secret or a cryptographic key as a credential for access, but allow several credentials at the same time. One example is SSH: a particular user may have several authorized public keys configured on the SSH server for access. For such systems users are advised to:

  • generate a new secret/key/credential using gokey version 0.2.0 or above
  • provision the new secret/key/credential in addition to the existing credential on the system
  • verify that the access or required system operation is still possible with the new secret/key/credential
  • revoke authorization for the existing/old credential from the system

Credit

This vulnerability was found by Théo Cusnir (@mister_mime) and responsibly disclosed through Cloudflare's bug bounty program.

References

@AlbertSPedersen AlbertSPedersen published to cloudflare/gokey Dec 2, 2025
Published by the National Vulnerability Database Dec 2, 2025
Published to the GitHub Advisory Database Dec 2, 2025
Reviewed Dec 2, 2025
Last updated Dec 2, 2025

Severity

High

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 Local
Attack Complexity Low
Attack Requirements Present
Privileges Required Low
User interaction None
Vulnerable System Impact Metrics
Confidentiality High
Integrity None
Availability None
Subsequent System Impact Metrics
Confidentiality High
Integrity High
Availability High

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:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:H

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.
(3rd percentile)

Weaknesses

Use of Insufficiently Random Values

The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers. Learn more on MITRE.

CVE ID

CVE-2025-13353

GHSA ID

GHSA-69jw-4jj8-fcxm

Source code

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