CyberSecBulletin
CVE-2024-13967NVD status: Deferred

EIBPORT V3 KNX: Session Fixation

CVE-2024-13967 is a high-severity session fixation vulnerability in EIBPORT V3 KNX from ABB, with a CVSS 3.1 base score of 8.8 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 EIBPORT V3 KNX versions: 3.9.8 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.52% 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 EIBPORT V3 KNX 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
ABBEIBPORT V3 KNX3.9.8 and earlierNot stated
ABBEIBPORT V3 KNX GSM3.9.8 and earlierNot 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
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:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by CNA (ch.abb.com).

Scoring systemScoreSeverityScored by
CVSS 4.09.4CriticalCNA (ch.abb.com)
CVSS 3.18.8HighCNA (ch.abb.com)

Official description

This vulnerability allows the successful attacker to gain unauthorized access to a configuration web page delivered by the integrated web Server of EIBPORT. This issue affects EIBPORT V3 KNX: through 3.9.8; EIBPORT V3 KNX GSM: through 3.9.8.

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

The underlying weakness: Session Fixation

Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions.

How developers prevent this class of flaw

  • Invalidate any existing session identifiers prior to authorizing a new user session.
  • For platforms such as ASP that do not generate new values for sessionid cookies, utilize a secondary cookie. In this approach, set a secondary cookie on the user's browser to a random value and set a session variable to the same value. If the session variable and the cookie value ever don't match, invalidate the session, and force the user to log on again.
  • 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 Session Fixation vulnerabilities (CWE-384)

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

Recent Session Fixation vulnerabilities

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