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CVE-2025-13942NVD status: Analyzed

EX3510-B0 firmware: Improper Neutralization of Special Elements used in an OS Command

CVE-2025-13942 is a critical-severity improper neutralization of special elements used in an OS command vulnerability in EX3510-B0 firmware from Zyxel, 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 EX3510-B0 firmware versions: <= 5.17(ABUP.15.1)C0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.17% chance of exploitation within 30 days, higher than 68% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Wx5610-b0 Firmware to 5.18\(acgj.0.5\)c0 or a later version.
  2. Update Lte3301-plus Firmware to 1.00\(abqu.9\)c0 or a later version.
  3. Update Nebula Lte3301-plus Firmware to 1.18\(acca.6\)v0 or a later version.
  4. Read the advisory on zyxel.com for workarounds and exact fixed builds.
  5. 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
ZyxelEX3510-B0 firmware<= 5.17(ABUP.15.1)C0Not stated
ZyxelWx5610-b0 Firmwarebefore 5.18\(acgj.0.5\)c05.18\(acgj.0.5\)c0
ZyxelLte3301-plus Firmwarebefore 1.00\(abqu.9\)c01.00\(abqu.9\)c0
ZyxelNebula Lte3301-plus Firmwarebefore 1.18\(acca.6\)v01.18\(acca.6\)v0
ZyxelNr7101 Firmwarebefore 1.00\(abuv.12\)b21.00\(abuv.12\)b2
ZyxelNebula Nr7101 Firmwarebefore 1.16\(accc.1\)v01.16\(accc.1\)v0
ZyxelDx4510-b0 Firmwarebefore 5.17\(abyl.10.1\)c05.17\(abyl.10.1\)c0
ZyxelDx4510-b1 Firmwarebefore 5.17\(abyl.10.1\)c05.17\(abyl.10.1\)c0
ZyxelEe6510-10 Firmwarebefore 5.19\(acjq.4.1\)c05.19\(acjq.4.1\)c0
ZyxelEmg6726-b10a Firmwarebefore 5.13\(abnp.8.2\)c15.13\(abnp.8.2\)c1
ZyxelEx2210-t0 Firmwarebefore 5.50\(acdi.2.4\)c05.50\(acdi.2.4\)c0
ZyxelEx3510-b1 Firmwarebefore 5.17\(abup.15.2\)c05.17\(abup.15.2\)c0
ZyxelEx5510-b0 Firmwarebefore 5.17\(abqx.11.1\)c05.17\(abqx.11.1\)c0
ZyxelEx5512-t0 Firmwarebefore 5.70\(aceg.5.4\)c05.70\(aceg.5.4\)c0
ZyxelEx7710-b0 Firmwarebefore 5.18\(acak.1.6\)c05.18\(acak.1.6\)c0
ZyxelVmg4927-b50a Firmwarebefore 5.13\(ably.10.2\)c05.13\(ably.10.2\)c0
ZyxelPx3321-t1 Firmwarebefore 5.44\(acjb.1.5\)c0; before 5.44\(achk.3\)c05.44\(acjb.1.5\)c0, 5.44\(achk.3\)c0
ZyxelPx5301-t0 Firmwarebefore 5.44\(ackb.0.6\)c05.44\(ackb.0.6\)c0

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 NVD.

Scoring systemScoreSeverityScored by
CVSS 3.19.8CriticalCNA (zyxel.com.tw)
CVSS 3.19.8CriticalNVD

Official description

A command injection vulnerability in the UPnP function of the Zyxel EX3510-B0 firmware versions through 5.17(ABUP.15.1)C0 could allow a remote attacker to execute operating system (OS) commands on an affected device by sending specially crafted UPnP SOAP requests.

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: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in EX3510-B0 firmware

All EX3510-B0 firmware vulnerabilities

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

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