GHSA-fq34-xw6c-fphf CVE-2025-57816 PYSEC-2026-1341
Fides Webserver API Rate Limiting Vulnerability in Proxied Environments
- Severity
- 0.0 / 10
- High · CVSS 4.0
- Exploit chance (EPSS)
- 0.43%
- Chance of exploitation in the next 30 days. Higher than 37.82% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-307 Improper Restriction of Excessive Authentication Attempts
- CWE-770 Allocation of Resources Without Limits or Throttling
- CWE-799 Improper Control of Interaction Frequency
- Fix
2.69.1- Upgrade ethyca-fides to this version or later
Description
Summary
The Fides Webserver API's built-in IP-based rate limiting is ineffective in environments with CDNs, proxies or load balancers. The system incorrectly applies rate limits based on directly connected infrastructure IPs rather than client IPs, and stores counters in-memory rather than in a shared store. This allows attackers to bypass intended rate limits and potentially cause denial of service.
This vulnerability only affects deployments relying on Fides's built-in rate limiting for protection. Deployments using external rate limiting solutions (WAFs, API gateways, etc.) are not affected.
Details
The vulnerability has two components:
- Rate limiting uses the immediate connection source IP instead of the actual client IP
- Rate limit counters are maintained in-memory per container rather than in a shared store
In production environments, these issues allow clients to exceed intended rate limits and enable attackers to trigger rate limits on infrastructure IPs, causing legitimate clients to receive 429 responses.
Impact
This vulnerability affects availability, allowing attackers to:
- Bypass rate limits, potentially leading to resource exhaustion
- Cause a denial of service for legitimate clients by deliberately triggering rate limits on infrastructure IPs
Patches
The vulnerability has been patched in Fides version 2.69.1. Users are advised to upgrade to this version or later to secure their systems against this threat.
Workarounds
There are no application-level workarounds. However, rate limiting may instead be implemented externally at the infrastructure level using a WAF, API Gateway, or similar technology.
Risk Level
This vulnerability has been assigned a severity of MEDIUM.
Affected versions
PyPI
| Package | Vulnerable | Fixed in |
|---|---|---|
| ethyca-fides | < 2.69.1 |
2.69.1 |
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.
ethyca-fides PyPI → 2.69.1
- pip
pip install --upgrade "ethyca-fides>=2.69.1"- poetry
poetry add "ethyca-fides>=2.69.1"- uv
uv add "ethyca-fides>=2.69.1"
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- Present
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- None
- Availability (vulnerable system)
- Low
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
CVSS 3.1 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Weakness
CWE-307: Improper Restriction of Excessive Authentication Attempts
The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame.
How to prevent it
- Architecture and Design: Common protection mechanisms include: Disconnecting the user after a small number of failed attempts Implementing a timeout Locking out a targeted account Requiring a computational task on the user's part.
- Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482]. Consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator. [REF-45]
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).
CWE-799: Improper Control of Interaction Frequency
The product does not properly limit the number or frequency of interactions that it has with an actor, such as the number of incoming requests.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-5qrq-9645-g5g2 ethyca-fides has a DOM-based XSS vulnerability in fides.js via fides_description override | High | Also affects ethyca-fides |
| GHSA-qx5f-ghc2-7g5c Ethyca Fides has a Privacy Request Identity Verification Bypass Vulnerability via Duplicate Detection | Medium | Also affects ethyca-fides |
| GHSA-hjfh-p8f5-24wr Fides Webserver API is Vulnerable to OAuth Client Privilege Escalation | High | Also affects ethyca-fides |
| GHSA-7q62-r88r-j5gw Fides has a Lack of Brute-Force Protections on Authentication Endpoints | Medium | Also affects ethyca-fides |
| GHSA-rpw8-82v9-3q87 Fides' Admin UI User Password Change Does Not Invalidate Current Session | Medium | Also affects ethyca-fides |
| GHSA-v7vm-rhmg-8j2r Password Policy Bypass Vulnerability in Fides Webserver User Accept Invite API | High | Also affects ethyca-fides |
| GHSA-c34r-238x-f7qx Remote Code Execution Vulnerability via SSTI in Fides Webserver Jinja Email Templating Engine | High | Also affects ethyca-fides |
| GHSA-2h46-8gf5-fmxv Timing-Based Username Enumeration Vulnerability in Fides Webserver Authentication | Medium | Also affects ethyca-fides |
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