CyberSecBulletin
CVE-2026-9457NVD status: Deferred

A8000RU: Improper Neutralization of Special Elements used in a Command

CVE-2026-9457 is a critical-severity improper neutralization of special elements used in a command vulnerability in A8000RU from TOTOLINK, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected A8000RU versions: 7.1cu.643_b20200521. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 2.09% chance of exploitation within 30 days, higher than 82% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of A8000RU you run against the affected versions below, and install the vendor's latest release.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
TOTOLINKA8000RU7.1cu.643_b20200521Not 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
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:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (vuldb.com).

Scoring systemScoreSeverityScored by
CVSS 4.08.9HighCNA (vuldb.com)
CVSS 3.19.8CriticalCNA (vuldb.com)
CVSS 2.010.0HighCNA (vuldb.com)

Official description

A vulnerability was determined in Totolink A8000RU 7.1cu.643_b20200521. The affected element is the function UploadFirmwareFile of the file /cgi-bin/cstecgi.cgi of the component Web Management Interface. This manipulation of the argument FileName causes os command injection. The attack is possible to be carried out remotely. The exploit has been publicly disclosed and may be utilized.

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

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in A8000RU

All A8000RU vulnerabilities

Recent Improper Neutralization of Special Elements used in a Command vulnerabilities

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