CVE-2023-40501: Critical Exposed Function RCE in LG Simple Editor

CVE-2023-40501 is a critical flaw in LG Simple Editor 3.21.0: the copyContent command has an exposed dangerous function that leads to remote code execution. NVD scores it 9.8 (Critical). LG told the Zero Day Initiative it will not fix it, so no patch exists. Restrict access to the application or remove it.

What's affected

The record lists one product and one version: LG Simple Editor 3.21.0 (the CPE vendor field reads lg). The weakness class is CWE-749.

The vulnerable code is the copyContent command, which exposes a dangerous function, and the advisory says an unauthenticated remote attacker can use it to execute code. Code execution as SYSTEM means full control of the host, so the record scores confidentiality, integrity and availability all as high.

No fixed version exists. The Zero Day Initiative advisory ZDI-23-1217 (tracked as ZDI-CAN-19945) says ZDI reported the issue to LG on 14 February 2023. On 8 August 2023 the vendor stated it does not plan to fix it now or in the future. ZDI then published it as a zero day advisory on 24 August 2023. NVD added the record on 3 May 2024. The record does not say whether versions other than 3.21.0 are affected, and the advisory names no safe version.

It is not in CISA's Known Exploited Vulnerabilities catalog, and the advisory does not say it is exploited in the wild.

How to check if you're exposed

There is no package feed to scan for this one, so exposure comes down to whether the application is installed and reachable. The record lists no authentication requirement, so network reachability is the only barrier.

On a Windows host, check whether LG Simple Editor is installed and which version:

Get-Package | Where-Object Name -like "*Simple Editor*"

Also look in Apps and features, because not every installer registers with that command. Then list listening sockets and match the owning process to the application:

netstat -ano | findstr LISTENING
tasklist /FI "PID eq 1234"

Replace 1234 with a process ID from the first command. If you find version 3.21.0 and the service answers from any network other than a trusted administration segment, treat the host as exposed. Add the host to your software inventory either way, so a later fix notice from LG reaches someone who can act on it.

What to do now

1. Inventory every host that has LG Simple Editor installed and record the version.
2. Remove network access you do not need. Block inbound connections to the service at the host firewall and the perimeter, and allow only named administrators.
3. If the product is not in active use, uninstall it. With no vendor fix, retirement is the only complete remedy.
4. Watch for unexpected child processes started by the application and for outbound connections from the host that you cannot explain.
5. Ask LG whether a patched version or a replacement exists, and recheck the Zero Day Initiative advisory for updates.

Why it matters

An exposed dangerous function is a design problem more than a typo. A capability that should be internal, such as one that handles files or runs commands, is reachable by outside callers. The fix is normally to remove the exposure or put strong checks in front of it, which only the vendor can do for a closed product.

Two records in this series name the same copyContent command with different tracking numbers, and the wording of one adds that the path is not validated. That suggests more than one problem around the same command, so a patch for one would not necessarily close the other. The vendor has said it will not patch this, which is the main reason the guidance here is about reducing exposure.

This is one of many records filed against LG Simple Editor 3.21.0 from the same ZDI batch, each tied to a different method. Each bug stands alone, so the safest reading is that the product as a whole should stay off untrusted networks.

Quick check

Sources

• Zero Day Initiative advisory ZDI-23-1217
• Safeguard Gold entry for CVE-2023-40501
• NVD record for CVE-2023-40501, as supplied in the Safeguard CVE dataset

Last reviewed: 19 October 2026.