CyberSecBulletin
CVE-2023-36489NVD status: Modified

TL-WR802N: Improper Neutralization of Special Elements used in an OS Command

Published Updated By the CyberSecBulletin desk

CVE-2023-36489 is a high-severity improper neutralization of special elements used in an OS command vulnerability in TL-WR802N from TP-Link, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. Affected TL-WR802N versions: firmware versions prior to 'TL-WR802N(JP)_V4_221008'. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.56% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update tl-wr802n_firmware to v4_221008 or a later version.
  2. Update tl-wr841n_firmware to v14_230506 or a later version.
  3. Update tl-wr902ac_firmware to v3_230506 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
TP-LinkTL-WR802Nfirmware versions prior to 'TL-WR802N(JP)_V4_221008'Not stated
TP-LinkTL-WR841Nfirmware versions prior to 'TL-WR841N(JP)_V14_230506'Not stated
TP-LinkTL-WR902ACfirmware versions prior to 'TL-WR902AC(JP)_V3_230506'Not stated
TP-Linktl-wr802n_firmware221008 up to, but not including, v4_221008v4_221008
TP-Linktl-wr841n_firmwarebefore v14_230506v14_230506
TP-Linktl-wr902ac_firmwarebefore v3_230506v3_230506

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
AdjacentThe attacker must be on the same local network segment.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
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:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Official description

Multiple TP-LINK products allow a network-adjacent unauthenticated attacker to execute arbitrary OS commands. Affected products/versions are as follows: TL-WR802N firmware versions prior to 'TL-WR802N(JP)_V4_221008', TL-WR841N firmware versions prior to 'TL-WR841N(JP)_V14_230506', and TL-WR902AC firmware versions prior to 'TL-WR902AC(JP)_V3_230506'.

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 an OS Command

The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command before 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.
  • For any data that will be used to generate a command to be executed, keep as much of that data out of external control as possible. For example, in web applications, this may require storing the data locally in the session's state instead of sending it out to the client in a hidden form field.
  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

More Improper Neutralization of Special Elements used in an OS Command vulnerabilities (CWE-78)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Recent Improper Neutralization of Special Elements used in an OS Command vulnerabilities

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