The specific API in TCBServiSign Windows Version from CHANGING Information Technology does not…
CVE-2024-40720 is a high-severity improper input validation vulnerability in TCBServiSign Windows Version from CHANGING Information Technology, 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 1.0.24.0318 as the first without the flaw, so updating TCBServiSign Windows Version to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.59% 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 TCBServiSign Windows Version to 1.0.24.0318 or a later version.
- Update tcbservisign to 1.0.24.0318 or a later version.
- Update Tcb Servisign to 1.0.24.0318 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 |
|---|---|---|---|
| CHANGING Information Technology | TCBServiSign Windows Version | before 1.0.24.0318 | 1.0.24.0318 |
| Changinginformationtechnology | tcbservisign | before 1.0.24.0318 | 1.0.24.0318 |
| Changingtec | Tcb Servisign | before 1.0.24.0318 | 1.0.24.0318 |
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 NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.8 | High | CNA (cert.org.tw) |
| CVSS 3.1 | 8.8 | High | NVD |
Official description
The specific API in TCBServiSign Windows Version from CHANGING Information Technology does not properly validate server-side input. When a user visits a spoofed website, unauthenticated remote attackers can modify the `HKEY_CURRENT_USER` registry to execute arbitrary commands.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
How developers prevent this class of flaw
- Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build recognizers for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses.
- Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
- Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- twcert.org.tw/en/cp-139-7971-d9584-2.htmlThird Party Advisory
- twcert.org.tw/tw/cp-132-7965-8285d-1.htmlThird Party Advisory
Other vulnerabilities in TCBServiSign Windows Version
- 8.8 High severity
Recent Improper Input Validation vulnerabilities
- 9.8 Critical severity
- 7.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
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