CyberSecBulletin
CVE-2024-7261NVD status: Analyzed

NWA1123ACv3 firmware: Improper Neutralization of Special Elements used in an OS Command

Published Updated By the CyberSecBulletin desk

CVE-2024-7261 is a critical-severity improper neutralization of special elements used in an OS command vulnerability in NWA1123ACv3 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 NWA1123ACv3 firmware versions: <= 6.70(ABVT.4); 6.70\(ABVT.4\) and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 11.4% chance of exploitation within 30 days, which is in the top 3.93% of all scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Nwa110ax Firmware to 7.00\(abtg.2\) or a later version.
  2. Update Nwa1123-ac Pro Firmware to 6.28\(abhd.3\) or a later version.
  3. Update Nwa130be Firmware to 7.00\(acil.2\) 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
ZyxelNWA1123ACv3 firmware<= 6.70(ABVT.4); 6.70\(ABVT.4\) and earlierNot stated
ZyxelWAC500 firmware<= 6.70(ABVS.4); 6.70\(ABVS.4\) and earlierNot stated
ZyxelWAX655E firmware<= 7.00(ACDO.1); 7.00\(ACDO.1\) and earlierNot stated
ZyxelWBE530 firmware<= 7.00(ACLE.1); 7.00\(ACLE.1\) and earlierNot stated
ZyxelUSG LITE 60AX firmwareV2.00(ACIP.2); V2.00\(ACIP.2\) and earlierNot stated
ZyxelNwa110ax Firmwarebefore 7.00\(abtg.2\)7.00\(abtg.2\)
ZyxelNwa1123-ac Pro Firmwarebefore 6.28\(abhd.3\)6.28\(abhd.3\)
ZyxelNwa130be Firmwarebefore 7.00\(acil.2\)7.00\(acil.2\)
ZyxelNwa210ax Firmwarebefore 7.00\(abtd.2\)7.00\(abtd.2\)
ZyxelNwa220ax-6e Firmwarebefore 7.00\(acco.2\)7.00\(acco.2\)
ZyxelNwa50ax Firmwarebefore 7.00\(abyw.2\)7.00\(abyw.2\)
ZyxelNwa50ax Pro Firmwarebefore 7.00\(acge.2\)7.00\(acge.2\)
ZyxelNwa55axe Firmwarebefore 7.00\(abzl.2\)7.00\(abzl.2\)
ZyxelNwa90ax Firmwarebefore 7.00\(accv.2\)7.00\(accv.2\)
ZyxelNwa90ax Pro Firmwarebefore 7.00\(acgf.2\)7.00\(acgf.2\)
ZyxelWac500h Firmwarebefore 6.70\(abwa.5\)6.70\(abwa.5\)
ZyxelWac6103d-i Firmwarebefore 6.28\(aaxh.3\)6.28\(aaxh.3\)
ZyxelWac6502d-s Firmwarebefore 6.28\(aase.3\)6.28\(aase.3\)
ZyxelWac6503d-s Firmwarebefore 6.28\(aasf.3\)6.28\(aasf.3\)
ZyxelWac6552d-s Firmwarebefore 6.28\(abio.3\)6.28\(abio.3\)
ZyxelWac6553d-e Firmwarebefore 6.28\(aasg.3\)6.28\(aasg.3\)
ZyxelWax300h Firmwarebefore 7.00\(achf.2\)7.00\(achf.2\)
ZyxelWax510d Firmwarebefore 7.00\(abtf.2\)7.00\(abtf.2\)
ZyxelWax610d Firmwarebefore 7.00\(abte.2\)7.00\(abte.2\)
ZyxelWax620d-6e Firmwarebefore 7.00\(accn.2\)7.00\(accn.2\)

Version data comes from the organisation that assigned the CVE; 4 further products are omitted here. 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 (zyxel.com.tw).

Official description

The improper neutralization of special elements in the parameter "host" in the CGI program of Zyxel NWA1123ACv3 firmware version 6.70(ABVT.4) and earlier, WAC500 firmware version 6.70(ABVS.4) and earlier, WAX655E firmware version 7.00(ACDO.1) and earlier, WBE530 firmware version 7.00(ACLE.1) and earlier, and USG LITE 60AX firmware version V2.00(ACIP.2) could allow an unauthenticated attacker to execute OS commands by sending a crafted cookie to a vulnerable device.

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 NWA1123ACv3 firmware

All NWA1123ACv3 firmware vulnerabilities

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

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