CyberSecBulletin
CVE-2024-12643NVD status: Deferred

tbm-client: Absolute Path Traversal

CVE-2024-12643 is a high-severity absolute path traversal vulnerability in tbm-client from Chunghwa Telecom, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected tbm-client versions: 0.3.15 through 0.3.20. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.33% 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 tbm-client you run against the affected versions below, and install the vendor's latest release.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
  3. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
Chunghwa Telecomtbm-client0.3.15 through 0.3.20Not 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
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H. Scored by CNA (cert.org.tw).

Official description

The tbm-client from Chunghwa Telecom has an Arbitrary File Delete vulnerability. The application sets up a simple local web server and provides APIs for communication with the target website. Due to the lack of CSRF protection in the APIs, unauthenticated remote attackers could use these APIs through phishing. Additionally, one of the APIs contains an Absolute Path Traversal vulnerability, allowing attackers to delete arbitrary files on the user's system.

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

The underlying weakness: Absolute Path Traversal

The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize absolute path sequences such as /abs/path that can resolve to a location that is outside of that directory.

How developers prevent this class of flaw

  • Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
  • 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 Absolute Path Traversal vulnerabilities (CWE-36)

Timeline

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

References

Other vulnerabilities in tbm-client

All tbm-client vulnerabilities

Recent Absolute Path Traversal vulnerabilities

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