Guardian: Session Fixation
CVE-2023-24477 is a high-severity session fixation vulnerability in Guardian from Nozomi Networks, with a CVSS 3.1 base score of 7.0 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists version 22.6.2 as the first without the flaw, so updating Guardian to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.15% 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 Guardian to 22.6.2 or a later version.
- Update CMC to 22.6.2 or a later version.
- Read the advisory on security.nozominetworks.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Nozomi Networks | Guardian | before 22.6.2 | 22.6.2 |
| Nozomi Networks | CMC | before 22.6.2 | 22.6.2 |
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
- LocalThe attacker needs local access or must trick a user into running something.
- 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:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 5.4 | Medium | CNA (nozominetworks.com) |
| CVSS 3.1 | 7.0 | High | CNA (nozominetworks.com) |
| CVSS 3.1 | 7.0 | High | NVD |
Official description
In certain conditions, depending on timing and the usage of the Chrome web browser, Guardian/CMC versions before 22.6.2 do not always completely invalidate the user session upon logout. Thus an authenticated local attacker may gain acces to the original user's session.
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.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in Guardian
- 7.2 High severity
- 7.2 High severity
- 7.5 High severity
- 7.4 High severity
- 8.1 High severity
- 7.5 High severity
Recent Session Fixation vulnerabilities
- 8.8 High severity
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.1 High severity
- 9.1 Critical severity
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