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SurrealDB vulnerable to memory exhaustion via nested functions and scripts

Moderate severity GitHub Reviewed Published Apr 10, 2025 in surrealdb/surrealdb • Updated Apr 10, 2025

Package

cargo surrealdb (Rust)

Affected versions

>= 2.2.0, < 2.2.2
>= 2.1.0, < 2.1.5
< 2.0.5

Patched versions

2.2.2
2.1.5
2.0.5

Description

In order to prevent DoS situations due to infinite recursions, SurrealDB implements a limit of nested calls for both native functions and embedded JavaScript functions.

However, in SurrealDB instances with embedded scripting functions enabled, it was found that this limit can be circumvented by utilizing both at the same time. If a native function contains JavaScript which issues a new query that calls that function, the recursion limit is not triggered.

Once executed, SurrealDB will follow the path of infinite recursions until the system runs out of memory, prior to the recursion limit being triggered.

This vulnerability can only affect SurrealDB servers explicitly enabling the scripting capability with --allow-scripting or
--allow-all and equivalent environment variables SURREAL_CAPS_ALLOW_SCRIPT=true and SURREAL_CAPS_ALLOW_ALL=true.

This issue was discovered and patched during an code audit and penetration test of SurrealDB by cure53, the severity defined within cure53's preliminary finding is Medium, matched by our CVSS v4 assessment.

Impact

For SurrealDB instances with embedded scripting functions enabled, this attack could be used to perform a DoS attack on the server by an authenticated user.

Patches

A patch has been created that further limits scripting function call limit recursion depth and disallows multiple calls to surreadb.query() to run in parallel in a scripting function.

  • Versions 2.0.5, 2.1.5, 2.2.2 and later are not affected by this issue.

Workarounds

Deny execution of embedded scripting functions through the configuration of capabilities by starting SurrealDB with the --deny-scripting flag or the equivalent environment variable SURREAL_CAPS_DENY_SCRIPT=true. This has a usability implication, although scripting functions are disabled by default.

References

SurrealDB Documentation - Capabilities
SurrealQL Documentation - Scripting Functions

References

@rowan-baker rowan-baker published to surrealdb/surrealdb Apr 10, 2025
Published to the GitHub Advisory Database Apr 10, 2025
Reviewed Apr 10, 2025
Last updated Apr 10, 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 Present
Privileges Required Low
User interaction None
Vulnerable System Impact Metrics
Confidentiality None
Integrity None
Availability High
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:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

EPSS score

Weaknesses

CVE ID

No known CVE

GHSA ID

GHSA-m7rc-8w7m-r9qr

Source code

Credits

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