CyberSecBulletin
CVE-2023-38902NVD status: Modified

rg-ew_series_routers_and_repeaters: Improper Neutralization of Special Elements used in a Command

Published Updated By the CyberSecBulletin desk

CVE-2023-38902 is a high-severity improper neutralization of special elements used in a command vulnerability in rg-ew_series_routers_and_repeaters from Ruijie, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected rg-ew_series_routers_and_repeaters versions: v.ew_3.0(1)B11P219. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 2.58% chance of exploitation within 30 days, higher than 85% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of rg-ew_series_routers_and_repeaters you run against the affected versions below, and install the vendor's latest release.

Affected products and versions

VendorProductAffected versionsFixed in
Ruijierg-ew_series_routers_and_repeatersv.ew_3.0(1)B11P219Not stated
Ruijierg-ew0Not stated
Ruijierg-s1930v.switch_3.0(1)b11p219Not stated
Ruijierg-egv.eg_3.0(1)b11p219Not stated
Ruijienbc_series_wireless_controllersv.ac_3.0(1)b11p219Not stated
RuijieRg-ew1200 Firmware3.0\(1\)b11p219Not stated
RuijieRg-ew1200g Pro Firmware3.0\(1\)b11p219Not stated
RuijieRg-ew1200r Firmware3.0\(1\)b11p219Not stated
RuijieRg-ew1300g Firmware3.0\(1\)b11p219Not stated
RuijieRg-ew1800gx Pro Firmware3.0\(1\)b11p219Not stated
RuijieRg-ew3000gx Pro Firmware3.0\(1\)b11p219Not stated
RuijieRg-ew300 Pro Firmware3.0\(1\)b11p219Not stated
RuijieRg-ew300r Firmware3.0\(1\)b11p219Not stated
RuijieRg-ew3200gx Pro Firmware3.0\(1\)b11p219Not stated
RuijieRg-nb3200-24gt4xs Firmware3.0\(1\)b11p219Not stated
RuijieRg-nbs1850gc Firmware3.0\(1\)b11p219Not stated
RuijieRg-nbs1850gc V2 Firmware3.0\(1\)b11p219Not stated
RuijieRg-nbs2000 Firmware3.0\(1\)b11p219Not stated
RuijieRg-nbs2009g-p Firmware3.0\(1\)b11p219Not stated
RuijieRg-nbs200 Firmware3.0\(1\)b11p219Not stated
RuijieRg-nbs2026g-p Firmware3.0\(1\)b11p219Not stated
RuijieRg-nbs2026g Firmware3.0\(1\)b11p219Not stated
RuijieRg-nbs226f Firmware3.0\(1\)b11p219Not stated
RuijieRg-nbs228f Firmware3.0\(1\)b11p219Not stated
RuijieRg-nbs252f Firmware3.0\(1\)b11p219Not stated

Version data comes from the organisation that assigned the CVE; 35 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
LowA basic user account is enough.
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:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Official description

A command injection vulnerability in RG-EW series home routers and repeaters v.EW_3.0(1)B11P219, RG-NBS and RG-S1930 series switches v.SWITCH_3.0(1)B11P219, RG-EG series business VPN routers v.EG_3.0(1)B11P219, EAP and RAP series wireless access points v.AP_3.0(1)B11P219, and NBC series wireless controllers v.AC_3.0(1)B11P219 allows an authorized attacker to execute arbitrary commands on remote devices by sending a POST request to /cgi-bin/luci/api/cmd via the remoteIp field.

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: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Technical write-ups (may include proof of concept)

Recent Improper Neutralization of Special Elements used in a Command vulnerabilities

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