Zkbio Time: Improper Neutralization of Formula Elements in a CSV File
CVE-2022-40472 is a high-severity improper neutralization of formula elements in a CSV file vulnerability in Zkbio Time from Zktec, with a CVSS 3.1 base score of 8.0 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, but only if a user takes part, for example by opening a link or file. Affected Zkbio Time versions: 8.0.7. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.15% chance of exploitation within 30 days, higher than 67% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Zkbio Time you run against the affected versions below, and install the vendor's latest release.
- 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 |
|---|---|---|---|
| Zktec | Zkbio Time | 8.0.7 | Not stated |
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
- LowA basic user account is enough.
- 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:L/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.0 | High | NVD |
| CVSS 3.1 | 8.0 | High | CISA (ADP) |
Official description
ZKTeco Xiamen Information Technology ZKBio Time 8.0.7 Build: 20220721.14829 was discovered to contain a CSV injection vulnerability. This vulnerability allows attackers to execute arbitrary code via a crafted payload injected into the Content text field of the Add New Message module.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Formula Elements in a CSV File
The product saves user-provided information into a Comma-Separated Value (CSV) file, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as a command when the file is opened by a spreadsheet product.
How developers prevent this class of flaw
- When generating CSV output, ensure that formula-sensitive metacharacters are effectively escaped or removed from all data before storage in the resultant CSV. Risky characters include '=' (equal), '+' (plus), '-' (minus), and '@' (at).
- If a field starts with a formula character, prepend it with a ' (single apostrophe), which prevents Excel from executing the formula.
- Certain implementations of spreadsheet software might disallow formulas from executing if the file is untrusted, or if the file is not authored by the current user.
More Improper Neutralization of Formula Elements in a CSV File vulnerabilities (CWE-1236)
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)
- the-it-wonders.blogspot.com/2022/09/zkbio-time-csv-injection.htmlExploit, Third Party Advisory
Recent Improper Neutralization of Formula Elements in a CSV File vulnerabilities
- 8.0 High severity
- 8.0 High severity
- 8.8 High severity
- 8.8 High severity
- 8.0 High severity
- 8.8 High severity
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