tl-er5120g: Improper Neutralization of Special Elements used in a Command
CVE-2023-43138 is a high-severity improper neutralization of special elements used in a command vulnerability in tl-er5120g from Tplink, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected tl-er5120g versions: 4.0_2.0.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 2.44% chance of exploitation within 30 days, higher than 85% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of tl-er5120g you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Tplink | tl-er5120g | 4.0_2.0.0 | Not stated |
| TP-Link | Tl-er5120g Firmware | 2.0.0 | 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
- 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
- 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:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
Official description
TPLINK TL-ER5120G 4.0 2.0.0 Build 210817 Rel.80868n has a command injection vulnerability, when an attacker adds NAPT rules after authentication, and the rule name has an injection point.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements used in a Command
The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.
How developers prevent this class of flaw
- If at all possible, use library calls rather than external processes to recreate the desired functionality.
- If possible, ensure that all external commands called from the program are statically created.
- Run time: Run time policy enforcement may be used in an allowlist fashion to prevent use of any non-sanctioned commands.
More Improper Neutralization of Special Elements used in a Command vulnerabilities (CWE-77)
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)
- github.com/7R4C4R/CVE/blob/main/TPLINK-TL-ER5120G/command%20injection/02/command%20injection02.mdExploit, Third Party Advisory
Other vulnerabilities in tl-er5120g
- 8.8 High severity
Recent Improper Neutralization of Special Elements used in a Command vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
- 9.8 Critical severity
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