CyberSecBulletin
CVE-2023-38293NVD status: Deferred

Certain software builds for the Nokia C200 and Nokia C100 Android devices contain a…

CVE-2023-38293 is a high-severity improper input validation vulnerability in c200 from Nokia, with a CVSS 3.1 base score of 7.3 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.78% chance of exploitation within 30 days, higher than 56% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of c200 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
Nokiac200Not specified in the recordNot 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
LowSome restricted data can be read.
Integrity
LowLimited modification of data is possible.
Availability
LowPerformance or availability is reduced.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L. Scored by CISA (ADP).

Official description

Certain software builds for the Nokia C200 and Nokia C100 Android devices contain a vulnerable, pre-installed app with a package name of com.tracfone.tfstatus (versionCode='31', versionName='12') that allows local third-party apps to execute arbitrary AT commands in its context (radio user) via AT command injection due to inadequate access control and inadequate input filtering. No permissions or special privileges are necessary to exploit the vulnerability in the com.tracfone.tfstatus app. No user interaction is required beyond installing and running a third-party app. The software build fingerprints for each confirmed vulnerable device are as follows: Nokia C200 (Nokia/Drake_02US/DRK:12/SP1A.210812.016/02US_1_080:user/release-keys and Nokia/Drake_02US/DRK:12/SP1A.210812.016/02US_1_040:user/release-keys) and Nokia C100 (Nokia/DrakeLite_02US/DKT:12/SP1A.210812.016/02US_1_270:user/release-keys, Nokia/DrakeLite_02US/DKT:12/SP1A.210812.016/02US_1_190:user/release-keys, Nokia/DrakeLite_02US/DKT:12/SP1A.210812.016/02US_1_130:user/release-keys, Nokia/DrakeLite_02US/DKT:12/SP1A.210812.016/02US_1_110:user/release-keys, Nokia/DrakeLite_02US/DKT:12/SP1A.210812.016/02US_1_080:user/release-keys, and Nokia/DrakeLite_02US/DKT:12/SP1A.210812.016/02US_1_050:user/release-keys). This malicious app sends a broadcast Intent to the receiver component named com.tracfone.tfstatus/.TFStatus. This broadcast receiver extracts a string from the Intent and uses it as an extra when it starts the com.tracfone.tfstatus/.TFStatusActivity activity component which uses the externally controlled string as an input to execute an AT command. There are two different injection techniques to successfully inject arbitrary AT commands to execute.

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

The underlying weakness: Improper Input Validation

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How developers prevent this class of flaw

  • Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build recognizers for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses.
  • Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
  • Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.

More Improper Input Validation vulnerabilities (CWE-20)

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

Recent Improper Input Validation vulnerabilities

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