CyberSecBulletin
CVE-2023-37565NVD status: Modified

WRC-1167GHBK-S: Improper Control of Generation of Code

Published Updated By the CyberSecBulletin desk

CVE-2023-37565 is a high-severity improper control of generation of code vulnerability in WRC-1167GHBK-S from Elecom, with a CVSS 3.1 base score of 8.0 out of 10. It can be exploited from the same local network by an attacker with a low-privileged account, without any action from a user. The record lists version 1.03 as the first without the flaw, so updating WRC-1167GHBK-S to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.53% 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 WRC-1167GHBK-S to 1.03 or a later version.
  2. Update WRC-1167GEBK-S to 1.03 or a later version.
  3. Update WRC-1167FEBK-S to 1.04 or a later version.
  4. Read the advisory on elecom.co.jp for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
ELECOMWRC-1167GHBK-Sv1.03 and earlier; before 1.031.03
ELECOMWRC-1167GEBK-Sv1.03 and earlier; before 1.031.03
ELECOMWRC-1167FEBK-Sv1.04 and earlier; before 1.041.04
ELECOMWRC-1167GHBK3-Av1.24 and earlier; before 1.241.24
ELECOMWRC-1167FEBK-Av1.18 and earlier; before 1.181.18
ElecomWrc-1167ghbk-s Firmware1.03 and earlierNot stated
ElecomWrc-1167gebk-s Firmware1.03 and earlierNot stated
ElecomWrc-1167febk-s Firmware1.04 and earlierNot stated
ElecomWrc-1167ghbk3-a Firmware1.24 and earlierNot stated
ElecomWrc-1167febk-a Firmware1.18 and earlierNot 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
AdjacentThe attacker must be on the same local network segment.
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:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Official description

Code injection vulnerability in ELECOM wireless LAN routers allows a network-adjacent authenticated attacker to execute arbitrary code by sending a specially crafted request. Affected products and versions are as follows: WRC-1167GHBK-S v1.03 and earlier, WRC-1167GEBK-S v1.03 and earlier, WRC-1167FEBK-S v1.04 and earlier, WRC-1167GHBK3-A v1.24 and earlier, and WRC-1167FEBK-A v1.18 and earlier.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Control of Generation of Code

The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.

How developers prevent this class of flaw

  • Refactor your program so that you do not have to dynamically generate code.
  • Run your code in a jail or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
  • Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.

More Improper Control of Generation of Code vulnerabilities (CWE-94)

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

Other vulnerabilities in WRC-1167GHBK-S

All WRC-1167GHBK-S vulnerabilities

Recent Improper Control of Generation of Code vulnerabilities

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