Gen5w L Firmware: Improper Privilege Management
CVE-2023-26243 is a high-severity improper privilege management vulnerability in Gen5w L Firmware from Hyundai, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected Gen5w L Firmware versions: ae_e_pe_eur.s5w_l001.001.211214. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.34% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Gen5w L Firmware you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Hyundai | Gen5w L Firmware | ae_e_pe_eur.s5w_l001.001.211214 | Not stated |
Version data comes from NVD's product matching. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- 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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
Official description
An issue was discovered in the Hyundai Gen5W_L in-vehicle infotainment system AE_E_PE_EUR.S5W_L001.001.211214. The decryption binary used to decrypt firmware files has an information leak that allows an attacker to read the AES key and initialization vector from memory. An attacker may exploit this to create custom firmware that may be installed in the IVI system. Then, an attacker may be able to install a backdoor in the IVI system that may allow him to control it, if it is connected to the Internet through Wi-Fi.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Privilege Management
The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.
How developers prevent this class of flaw
- Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
- Follow the principle of least privilege when assigning access rights to entities in a software system.
- Consider following the principle of separation of privilege. Require multiple conditions to be met before permitting access to a system resource.
More Improper Privilege Management vulnerabilities (CWE-269)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Technical write-ups (may include proof of concept)
- sowhat.iit.cnr.it:8443/can-work/chimaeraExploit, Third Party Advisory
- sowhat.iit.cnr.it:8443/can-work/chimaera/-/blob/main/Report/IIT-01-2023.pdfExploit, Third Party Advisory
Other references
- sowhat.iit.cnr.itNot Applicable
Other vulnerabilities in Gen5w L Firmware
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
Recent Improper Privilege Management vulnerabilities
- 8.8 High severity
- 9.8 Critical severity
- 7.8 High severity
- 7.8 High severity
- 8.8 High severity
- 8.2 High severity
Spotted an error? Tell us.