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CVE-2024-43661NVD status: Deferred

Iocharger firmware for AC models: Stack-based Buffer Overflow

CVE-2024-43661 is a high-severity stack-based buffer overflow vulnerability in Iocharger firmware for AC models from Iocharger, with a CVSS 4.0 base score of 7.1 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. The record lists version 24120701 as the first without the flaw, so updating Iocharger firmware for AC models to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.51% 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 Iocharger firmware for AC models to 24120701 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
IochargerIocharger firmware for AC modelsbefore 2412070124120701

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.
Attack requirements
NoneThe attack does not depend on a particular deployment or configuration.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Confidentiality (vulnerable system)
NoneNo loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
NoneNo loss of integrity on the vulnerable system.
Availability (vulnerable system)
HighSerious loss of availability on the vulnerable system.
Confidentiality (other systems)
NoneNo loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
NoneNo loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
NoneNo loss of availability on systems beyond the vulnerable one.

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:I/V:X/RE:X/U:X. Scored by CNA (divd.nl).

Scoring systemScoreSeverityScored by
CVSS 4.07.1HighCNA (divd.nl)
CVSS 3.19.8CriticalCISA (ADP)

Official description

The <redacted>.so library, which is used by <redacted>, is vulnerable to a buffer overflow in the code that handles the deletion of certificates. This buffer overflow can be triggered by providing a long file path to the <redacted> action of the <redacted>.exe CGI binary or to the <redacted>.sh CGI script. This binary or script will write this file path to <redacted>, which is then read by <redacted>.so This issue affects Iocharger firmware for AC models before version 24120701. Likelihood: Moderate – An attacker will have to find this exploit by either obtaining the binaries involved in this vulnerability, or by trial and error. Furthermore, the attacker will need a (low privilege) account to gain access to the <redacted>.exe CGI binary or <redacted>.sh script to trigger the vulnerability, or convince a user with such access send an HTTP request that triggers it. Impact: High – The <redacted> process, which we assume is responsible for OCPP communication, will keep crashing after performing the exploit. This happens because the buffer overflow causes the process to segfault before <redacted> is removed. This means that, even though <redacted> is automatically restarted, it will crash again as soon as it tries to parse the text file. CVSS clarification. The attack can be executed over any network connection the station is listening to and serves the web interface (AV:N), and there are no additional security measure sin place that need to be circumvented (AC:L), the attack does not rely on preconditions (AT:N). The attack does require authentication, but the level of authentication is irrelevant (PR:L), it does not require user interaction (UI:N). The attack leads to reducred availability of the device (VC:N/VI:N/VA:H). THere is not impact on subsequent systems. (SC:N/SI:N/SA:N). Alltough this device is an EV charger handing significant amounts of power, we do not forsee a safety impact. The attack can be automated (AU:Y). Because the DoS condition is written to disk persistantly, it cannot be recovered by the user (R:I).

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

The underlying weakness: Stack-based Buffer Overflow

The product writes past the end of a buffer that was allocated on the stack.

How developers prevent this class of flaw

  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
  • Use an abstraction library to abstract away risky APIs. Not a complete solution.
  • Implement and perform bounds checking on input.

More Stack-based Buffer Overflow vulnerabilities (CWE-121)

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 Iocharger firmware for AC models

All Iocharger firmware for AC models vulnerabilities

Recent Stack-based Buffer Overflow vulnerabilities

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