Control: Improper Neutralization of Special Elements in Output Used by a Downstream Component
CVE-2023-25719 is a high-severity improper neutralization of special elements in output used by a downstream component vulnerability in Control from ConnectWise, 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. The record lists version 22.9.10032 as the first without the flaw, so updating Control to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.06% chance of exploitation within 30 days, higher than 65% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Control to 22.9.10032 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
- 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
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Connectwise | Control | before 22.9.10032 | 22.9.10032 |
Version data comes from NVD's product matching. 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 NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.8 | High | NVD |
| CVSS 3.1 | 8.8 | High | CISA (ADP) |
Official description
ConnectWise Control before 22.9.10032 (formerly known as ScreenConnect) fails to validate user-supplied parameters such as the Bin/ConnectWiseControl.Client.exe h parameter. This results in reflected data and injection of malicious code into a downloaded executable. The executable can be used to execute malicious queries or as a denial-of-service vector. NOTE: this CVE Record is only about the parameters, such as the h parameter (this CVE Record is not about the separate issue of signed executable files that are supposed to have unique configurations across customers' installations).
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements in Output Used by a Downstream Component
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
How developers prevent this class of flaw
- Programming languages and supporting technologies might be chosen which are not subject to these issues.
- Utilize an appropriate mix of allowlist and denylist parsing to filter control-plane syntax from all input.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Technical write-ups (may include proof of concept)
- cybir.com/2022/cve/hijacking-connectwise-control-and-ddos/Exploit, Third Party Advisory
Other references
Other vulnerabilities in Control
- 9.8 Critical severity
Recent Improper Neutralization of Special Elements in Output Used by a Downstream Component vulnerabilities
- 7.5 High severity
- 7.1 High severity
- 8.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.8 High severity
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