CyberSecBulletin
CVE-2023-46725NVD status: Modified

foodcoopshop: Time-of-check Time-of-use (TOCTOU) Race Condition

CVE-2023-46725 is a high-severity time-of-check time-of-use (TOCTOU) race condition vulnerability in foodcoopshop, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected foodcoopshop versions: >= 3.2.0, < 3.6.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.56% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of foodcoopshop you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
Foodcoopshopfoodcoopshop>= 3.2.0, < 3.6.1Not stated

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
HighSuccess depends on conditions outside the attacker's control.
Privileges required
LowA basic user account is enough.
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
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

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

Scoring systemScoreSeverityScored by
CVSS 3.18.1HighCNA (github.com)
CVSS 3.17.5HighNVD

Official description

FoodCoopShop is open source software for food coops and local shops. Versions starting with 3.2.0 prior to 3.6.1 are vulnerable to server-side request forgery. In the Network module, a manufacturer account can use the `/api/updateProducts.json` endpoint to make the server send a request to an arbitrary host. This means that the server can be used as a proxy into the internal network where the server is. Furthermore, the checks on a valid image are not adequate, leading to a time of check time of use issue. For example, by using a custom server that returns 200 on HEAD requests, then return a valid image on first GET request and then a 302 redirect to final target on second GET request, the server will copy whatever file is at the redirect destination, making this a full SSRF. Version 3.6.1 fixes this vulnerability.

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

The underlying weakness: Time-of-check Time-of-use (TOCTOU) Race Condition

The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.

How developers prevent this class of flaw

  • The most basic advice for TOCTOU vulnerabilities is to not perform a check before the use. This does not resolve the underlying issue of the execution of a function on a resource whose state and identity cannot be assured, but it does help to limit the false sense of security given by the check.
  • When the file being altered is owned by the current user and group, set the effective gid and uid to that of the current user and group when executing this statement.
  • Limit the interleaving of operations on files from multiple processes.

More Time-of-check Time-of-use (TOCTOU) Race Condition vulnerabilities (CWE-367)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other references

Recent Time-of-check Time-of-use (TOCTOU) Race Condition vulnerabilities

Spotted an error? Tell us.