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GHSA-7m27-7ghc-44w9 CVE-2024-56332

Next.js Allows a Denial of Service (DoS) with Server Actions

Medium npm
Severity
5.3 / 10
Medium · CVSS 3.1
Exploit chance (EPSS)
0.80%
Chance of exploitation in the next 30 days. Higher than 56.67% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-770 Allocation of Resources Without Limits or Throttling
Fix
13.5.8
Upgrade next to this version or later

Description

Impact

A Denial of Service (DoS) attack allows attackers to construct requests that leaves requests to Server Actions hanging until the hosting provider cancels the function execution.

Note: Next.js server is idle during that time and only keeps the connection open. CPU and memory footprint are low during that time.

Deployments without any protection against long running Server Action invocations are especially vulnerable. Hosting providers like Vercel or Netlify set a default maximum duration on function execution to reduce the risk of excessive billing.

This is the same issue as if the incoming HTTP request has an invalid Content-Length header or never closes. If the host has no other mitigations to those then this vulnerability is novel.

This vulnerability affects only Next.js deployments using Server Actions.

Patches

This vulnerability was resolved in Next.js 14.2.21, 15.1.2, and 13.5.8. We recommend that users upgrade to a safe version.

Workarounds

There are no official workarounds for this vulnerability.

Credits

Thanks to the PackDraw team for responsibly disclosing this vulnerability.

Affected versions

npm

PackageVulnerableFixed in
next
>= 13.0.0, < 13.5.8
13.5.8
next
>= 14.0.0, < 14.2.21
14.2.21
next
>= 15.0.0, < 15.1.2
15.1.2

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.

next npm → 13.5.8

npm
npm install next@13.5.8
yarn
yarn add next@13.5.8
pnpm
pnpm add next@13.5.8

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

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-673q-mjm6-r5xr
Next.js: Unauthenticated Remote Code Execution in `use cache` functions returning typed arrays
Critical Also affects next
GHSA-2464-fhr4-w9xw
Next.js: Unauthenticated Remote Code Execution in Image Optimization API when SVG files are used
Critical Also affects next
GHSA-p3m5-59mp-jv5r
Next.js: Denial of Service in App Router using Server Actions
High Also affects next
GHSA-3w37-wq28-93x7
Next.js: Pending `use cache` fill can leak Draft Mode content into regular responses and persisted pages
Medium Also affects next
GHSA-4jqv-mc3x-m676
Next.js has cache poisoning of SSG and ISR pages in self-hosted applications
Medium Also affects next
GHSA-39w2-rjm5-chcv
Next.js has information disclosure in development server's Model Context Protocol endpoint
Medium Also affects next
GHSA-f87g-xv8r-7p7x
Next.js has information disclosure in App Router metadata image routes via dynamicParams bypass
Medium Also affects next
GHSA-mcj8-r9mp-w47p
Next.js has cache poisoning in SSG/ISR rendering that leads to cross-user content substitution and persistent denial of service
Medium Also affects next
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