2FAuth: Server-Side Request Forgery
CVE-2024-52598 is a high-severity server-side request forgery vulnerability in 2FAuth from Bubka, 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 5.4.1 as the first without the flaw, so updating 2FAuth to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.59% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update 2FAuth to 5.4.1 or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
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 system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | CNA (github.com) |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
2FAuth is a web app to manage Two-Factor Authentication (2FA) accounts and generate their security codes. Two interconnected vulnerabilities exist in version 5.4.1 a SSRF and URI validation bypass issue. The endpoint at POST /api/v1/twofaccounts/preview allows setting a remote URI to retrieve the image of a 2fa site. By abusing this functionality, it is possible to force the application to make a GET request to an arbitrary URL, whose content will be stored in an image file in the server if it looks like an image. Additionally, the library does some basic validation on the URI, attempting to filter our URIs which do not have an image extension. However, this can be easily bypassed by appending the string `#.svg` to the URI. The combination of these two issues allows an attacker to retrieve URIs accessible from the application, as long as their content type is text based. If not, the request is still sent, but the response is not reflected to the attacker. Version 5.4.1 fixes the issues.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Server-Side Request Forgery
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
How developers prevent this class of flaw
- If there is a known list of applications, IP, hostname, and/or domains to which the product is allowed to communicate, then use allowlists to ensure that outgoing requests are restricted to these known entities. The allowlists could be in the application code or possibly enforced by firewalls or network segmentation.
- If the product is expected to be able to connect to arbitrary IP addresses or domains, consider using a denylist that includes private network addresses, internal domain names, etc. The denylist could be in the application code or possibly enforced by firewalls or network segmentation.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in 2FAuth
- 8.1 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.1 Critical severity
Recent Server-Side Request Forgery vulnerabilities
- 7.7 High severity
- 9.1 Critical severity
- 7.5 High severity
- 8.8 High severity
- 8.8 High severity
- 8.6 High severity
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