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SurrealDB bypass of deny-net flags via redirect results in server-side request forgery (SSRF)

Moderate severity GitHub Reviewed Published Apr 10, 2025 in surrealdb/surrealdb • Updated Apr 11, 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

SurrealDB offers http functions that can access external network endpoints. A typical, albeit not recommended configuration would be to start SurrealDB with all network connections allowed with the exception of a deny list. For example, surreal start --allow-net --deny-net 10.0.0.0/8 will allow all network connections except to the 10.0.0.0/8 block.

An authenticated user of SurrealDB can use redirects to bypass this restriction. For example by hosting a server on the public internet which redirects to the IP addresses blocked by the administrator of the SurrealDB server via HTTP 301 or 307 response codes.

When sending SurrealDB statements containing the http::* functions to the attacker controlled host, the SurrealDB server will follow the redirects to the blocked IP address. Because the statements also return the responses to the attacker, this issue constitutes a full SSRF vulnerability.

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

Impact

The impact of this vulnerability is circumvention of the --deny-net capability and resulting impact on systems external to SurrealDB. The ultimate impact is dependent on the deployment scenario.

For example, if the SurrealDB server blocks requests to internal and private IP addresses because they run services which don't require authentication, such as AWS deployments using IMDSv1, the attacker can access these internal endpoints directly, and potentially retrieve or even alter sensitive information and credentials.

The circumvention could also be used to redirect traffic to the SurrealDB port, providing a low level of impact to availability.

Patches

A patch has been created that adds an HTTP redirect limit, and checks HTTP redirects against allowed network targets, preventing redirections to disallowed uri's.

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

Workarounds

The possibility of this vulnerability being exploited can be reduced by following an allowlist approach to enabling the http capability surreal start --allow-net 10.0.0.0/8 or using the equivalent SURREAL_CAPS_ALLOW_NET environment variable, where endpoints allowed are fully trusted and are not controlled by regular users.

The network access capability can be disabled, using --deny-net or the equivalent SURREAL_CAPS_DENY_NET environment variable without specifying targets, with impact to SurrealDB functionality.

As the impact of this vulnerability depends on the security of the deployment environment of SurrealDB, best practices should be followed within that environment.

References

#5597
SurrealDB Documentation - Environment Variables
SurrealDB Documentation - Capabilities
SurrealDB Documentation - Network Access Capability

References

@rowan-baker rowan-baker published to surrealdb/surrealdb Apr 10, 2025
Published to the GitHub Advisory Database Apr 11, 2025
Reviewed Apr 11, 2025
Last updated Apr 11, 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 Low
Availability Low
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:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:L/SC:H/SI:H/SA:H

EPSS score

Weaknesses

CVE ID

No known CVE

GHSA ID

GHSA-5q9x-554g-9jgg

Source code

Credits

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