GHSA-65rj-r9fh-jp2v
SurrealDB vulnerable to pre-auth memory amplification via unbounded `/sql` WebSocket frames
- Severity
- 5.3 / 10
- Medium · CVSS 3.1
- Exploit chance (EPSS)
- —
- No score published
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-770 Allocation of Resources Without Limits or Throttling
- Fix
3.1.0- Upgrade surrealdb to this version or later
Description
An anonymous caller could degrade /sql availability by streaming WebSocket frames many times larger than the operator-configured per-connection limit. The /sql upgrade handler accepted anonymous connections and did not propagate SURREAL_WEBSOCKET_MAX_MESSAGE_SIZE to the WebSocket protocol layer — incoming bytes accumulated in the per-connection read buffer before check_anon could reject the query, so the memory cost was incurred regardless of whether the caller could ever execute SurrealQL. The same upgrade path also silently ignored --deny-http sql and --deny-arbitrary-query * for authenticated callers, but that secondary effect does not grant new permissions.
Impact
SURREAL_WEBSOCKET_MAX_MESSAGE_SIZE is not applied to anonymous /sql connections, so each connection can buffer up to the WebSocket library defaults (16 MiB per frame, 64 MiB per reassembled message) of in-flight bytes regardless of the operator's configured limit. Holding this much memory pinned requires actively streaming bytes into the connection, so an attacker has to maintain bandwidth across many concurrent connections to consume meaningful memory. Within that constraint the result is degraded availability for legitimate /sql clients; on memory-constrained deployments the process may be OOM-killed and restarted during the attack rather than denied service outright.
Separately, --deny-http sql and --deny-arbitrary-query * were not enforced on the WebSocket, so SurrealQL operations the operator had configured to refuse could still be issued by any authenticated principal that already held the corresponding data permissions. This is a configuration-correctness defect — the bypass does not grant new permissions.
Patches
A patch has been introduced that performs the two capability checks before calling on_upgrade and applies the same per-connection size limits used by /rpc. The capability checks enforce the operator's configured deny flags; they do not change what any authenticated principal is permitted to do.
- Versions 3.1.0 and later are not affected by this issue.
Workarounds
Affected users who are unable to update should refuse GET /sql requests carrying Upgrade: websocket at a reverse proxy, or apply per-connection frame size limits at the reverse proxy.
Affected versions
crates.io
| Package | Vulnerable | Fixed in |
|---|---|---|
| surrealdb | < 3.1.0 |
3.1.0 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
surrealdb crates.io → 3.1.0
- cargo
cargo update -p surrealdb --precise 3.1.0
Severity breakdown
CVSS 3.1 5.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Weakness
CWE-770: Allocation of Resources Without Limits or Throttling
The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
How to prevent it
- Requirements: Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
- Architecture and Design: Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.
- Architecture and Design: Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place, and it will help the administrator to identify who is committing the abuse. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.
- Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
- Architecture and Design: For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- Architecture and Design: Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, typically by using increasing time delays uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed. The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question. The second solution can be difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply requires more resources on the part of the attacker.
- Architecture and Design: Ensure that protocols have specific limits of scale placed on them.
- Architecture and Design, Implementation: If the program must fail, ensure that it fails gracefully (fails closed). There may be a temptation to simply let the program fail poorly in cases such as low memory conditions, but an attacker may be able to assert control before the software has fully exited. Alternately, an uncontrolled failure could cause cascading problems with other downstream components; for example, the program could send a signal to a downstream process so the process immediately knows that a problem has occurred and has a better chance of recovery. Ensure that all failures in resource allocation place the system into a safe posture.
- Operation, Architecture and Design: Use quotas or other resource-limiting settings provided by the operating system or environment. For example, when managing system resources in POSIX, setrlimit() can be used to set limits for certain types of resources, and getrlimit() can determine how many resources are available. However, these functions are not available on all operating systems. When the current levels get close to the maximum that is defined for the application (see CWE-770), then limit the allocation of further resources to privileged users; alternately, begin releasing resources for less-privileged users. While this mitigation may protect the system from attack, it will not necessarily stop attackers from adversely impacting other users. Ensure that the application performs the appropriate error checks and error handling in case resources become unavailable (CWE-703).
References
Packages
Other links
Timeline
- Published
- Last updated by the source
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-8rw6-p7m8-63jp SurrealDB: Array element-level (field.*) SELECT permissions leak denied elements to record users | High | Also affects surrealdb |
| GHSA-848m-r628-vrxw SurrealDB: Custom API route lets authenticated callers override namespace/database scope via URL path | High | Also affects surrealdb |
| GHSA-m3c3-78fh-w3w7 SurrealDB allows bypass of deny-net flags via DNS resolution | High | Also affects SurrealDB |
| GHSA-whwg-vh4f-pmmf SurrealDB: Edge PERMISSIONS FOR delete bypassed when a connected node is deleted | Medium | Also affects surrealdb |
| GHSA-fwg2-gr34-q3w8 SurrealDB: ES512 silently downgraded to ES384 due to jsonwebtoken crate limitation | Medium | Also affects surrealdb |
| GHSA-c8jx-96c9-8xrp SurrealDB: Field-level SELECT permissions bypassed via indexed COUNT fast paths | Medium | Also affects surrealdb |
| GHSA-wp87-mgvq-5j93 SurrealDB: USE NS/DB implicit creation bypasses DEFINE authorization | Medium | Also affects surrealdb |
| GHSA-97vg-427p-8hx5 SurrealDB: Port-specific --deny-net rules silently bypassed on HTTP redirect | Medium | Also affects surrealdb |
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