CyberSecBulletin
CVE-2023-36827NVD status: Modified

fides: Improper Limitation of a Pathname to a Restricted Directory

CVE-2023-36827 is a high-severity improper limitation of a pathname to a restricted directory vulnerability in fides from Ethyca, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 2.15.1 as the first without the flaw, so updating fides to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.49% chance of exploitation within 30 days, higher than 75% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update fides to 2.15.1 or a later version.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Ethycafides< 2.15.1; before 2.15.12.15.1

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.5HighCNA (github.com)
CVSS 3.17.5HighNVD

Official description

Fides is an open-source privacy engineering platform for managing the fulfillment of data privacy requests in a runtime environment, and the enforcement of privacy regulations in code. A path traversal (directory traversal) vulnerability affects fides versions lower than version `2.15.1`, allowing remote attackers to access arbitrary files on the fides webserver container's filesystem. The vulnerability is patched in fides `2.15.1`. If the Fides webserver API is not directly accessible to attackers and is instead deployed behind a reverse proxy as recommended in Ethyca's security best practice documentation, and the reverse proxy is an AWS application load balancer, the vulnerability can't be exploited by these attackers. An AWS application load balancer will reject this attack with a 400 error. Additionally, any secrets supplied to the container using environment variables rather than a `fides.toml` configuration file are not affected by this vulnerability.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Limitation of a Pathname to a Restricted Directory

The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

How developers prevent this class of flaw

  • 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.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
  • Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth.

More Improper Limitation of a Pathname to a Restricted Directory vulnerabilities (CWE-22)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Advisories

Other vulnerabilities in fides

All fides vulnerabilities

Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities

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