POS terminals: Improper Neutralization of Special Elements in Output Used by a Downstream Component
CVE-2023-42136 is a high-severity improper neutralization of special elements in output used by a downstream component vulnerability in POS terminals from PAX Technology, with a CVSS 3.1 base score of 7.8 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. Affected POS terminals versions: 11.1.50_20230614 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.48% 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
- Check which version of POS terminals you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| PAX Technology | POS terminals | 11.1.50_20230614 and earlier | Not stated |
| Paxtechnology | paydroid | 8.1.0_sagittarius_11.1.50_20230614 and earlier | Not stated |
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
- LowNo special conditions are needed; the attack works reliably.
- 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:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA (cert.pl) |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
PAX Android based POS devices with PayDroid_8.1.0_Sagittarius_V11.1.50_20230614 or earlier can allow the execution of arbitrary commands with system account privilege by shell injection starting with a specific word. The attacker must have shell access to the device in order to exploit this vulnerability.
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
Third-party and government advisories
- cert.pl/en/posts/2024/01/CVE-2023-4818/Third Party Advisory
- cert.pl/posts/2024/01/CVE-2023-4818/Third Party Advisory
Technical write-ups (may include proof of concept)
- blog.stmcyber.com/pax-pos-cves-2023/Exploit, Third Party Advisory
Other references
- ppn.paxengine.com/release/developmentPermissions Required
Other vulnerabilities in POS terminals
- 7.8 High severity
Recent Improper Neutralization of Special Elements in Output Used by a Downstream Component vulnerabilities
- 7.6 High severity
- 9.8 Critical severity
- 7.5 High severity
- 9.6 Critical severity
- 9.6 Critical severity
- 9.8 Critical severity
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