AppSync: Session Fixation
CVE-2022-22551 is a high-severity session fixation vulnerability in AppSync from Dell, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists version 4.4 as the first without the flaw, so updating AppSync to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.4% 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 AppSync to 4.4 or a later version.
- Update Emc Appsync to 4.4.0.0 or a later version.
- Read the advisory on dell.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Dell | AppSync | before 4.4 | 4.4 |
| Dell | Emc Appsync | before 4.4.0.0 | 4.4.0.0 |
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
- AdjacentThe attacker must be on the same local network segment.
- 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
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.3 | High | CNA (emc.com) |
| CVSS 3.1 | 8.8 | High | NVD |
| CVSS 2.0 | 5.8 | Medium | NVD |
Official description
DELL EMC AppSync versions 3.9 to 4.3 use GET request method with sensitive query strings. An Adjacent, unauthenticated attacker could potentially exploit this vulnerability, and hijack the victim 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 AppSync
- 7.3 High severity
- 7.3 High severity
- 7.3 High severity
- 7.5 High severity
- 9.8 Critical severity
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