CyberSecBulletin
CVE-2024-45415NVD status: Deferred

zxhn_z500_firmware: Stack-based Buffer Overflow

Published Updated By the CyberSecBulletin desk

CVE-2024-45415 is a critical-severity stack-based buffer overflow vulnerability in zxhn_z500_firmware from ZTE, 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 zxhn_z500_firmware versions: V1.0.1.1B2.1000. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.48% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of zxhn_z500_firmware you run against the affected versions below, and install the vendor's latest release.
  2. 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
ZTEzxhn_z500_firmwareV1.0.1.1B2.1000Not stated
ZTEzxhn_e500_firmwareV1.0.1.1B2.1000Not stated
ZTEzxhn_h108n_firmwareV2.6.20.ROST12Not stated
ZTEzxhn_e2615_firmwareV1.0.1Not stated
ZTEzxhn_e2603_firmwareV1.0.1Not stated
ZTEzxhn_e2618_firmwareV1.0.0.2B4.3000Not stated
ZTEzxhn_e1600_firmwareV1.0.0.2B1.1000Not stated
ZTEzxhn_h338a_firmwareV1.5.0_H3A.1T9P1-oNot stated
ZTEzxhn_h168n_firmwareV3.5.5_CO.1T1Not stated
ZTEzxhn_h168a_firmwareTTN.1T1_211029Not 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
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 CISA (ADP).

Official description

The HTTPD binary in multiple ZTE routers has a stack-based buffer overflow vulnerability in check_data_integrity function. This function is responsible for validating the checksum of data in post request. The checksum is sent encrypted in the request, the function decrypts it and stores the checksum on the stack without validating it. An unauthenticated attacker can get RCE as root by exploiting this vulnerability.

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 zxhn_z500_firmware

All zxhn_z500_firmware vulnerabilities

Recent Stack-based Buffer Overflow vulnerabilities

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