CyberSecBulletin
CVE-2019-3929Exploited in the wildNVD status: Analyzed

Crestron Multiple Products Command Injection

Published Updated By the CyberSecBulletin desk

CVE-2019-3929 is a critical-severity improper neutralization of special elements used in an OS command vulnerability in Crestron AirMedia, Barco WePresent, Extron ShareLink, Teq AV IT WIPS710, SHARP PN-L703WA, Optoma WPS-Pro, Blackbox HD WPS, InFocus LiteShow3, and InFocus LiteShow4. from Crestron, 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 Crestron AirMedia, Barco WePresent, Extron ShareLink, Teq AV IT WIPS710, SHARP PN-L703WA, Optoma WPS-Pro, Blackbox HD WPS, InFocus LiteShow3, and InFocus LiteShow4. versions: Crestron AM-100 firmware 1.6.0.2; Crestron AM-101 firmware 2.7.0.1; Barco wePresent WiPG-1000P firmware 2.3.0.10, and others listed below. The record does not name a fixed version, so check the vendor advisory. CISA added it to the Known Exploited Vulnerabilities catalogue on April 15, 2022, which means attacks have been observed in the wild.

Patch now

Attackers are already exploiting this vulnerability, according to CISA.

What to do

  1. Update Wepresent Wipg-1600w Firmware to 2.4.1.19 or a later version.
  2. CISA's required action: Apply updates per vendor instructions.
  3. 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
CrestronCrestron AirMedia, Barco WePresent, Extron ShareLink, Teq AV IT WIPS710, SHARP PN-L703WA, Optoma WPS-Pro, Blackbox HD WPS, InFocus LiteShow3, and InFocus LiteShow4.Crestron AM-100 firmware 1.6.0.2; Crestron AM-101 firmware 2.7.0.1; Barco wePresent WiPG-1000P firmware 2.3.0.10; Barco wePresent WiPG-1600W before firmware 2.4.1.19; Extron ShareLink 200/250 firmware 2.0.3.4; Teq AV IT WIPS710 firmware 1.1.0.7; SHARP PN-L703WA firmware 1.4.2.3; Optoma WPS-Pro firmware 1.0.0.5; and 3 more rangesNot stated
CrestronAm-100 Firmware1.6.0.2Not stated
CrestronAm-101 Firmware2.7.0.2Not stated
BarcoWepresent Wipg-1000p Firmware2.3.0.10Not stated
BarcoWepresent Wipg-1600w Firmwarebefore 2.4.1.192.4.1.19
ExtronSharelink 200 Firmware2.0.3.4Not stated
ExtronSharelink 250 Firmware2.0.3.4Not stated
TeqavitWips710 Firmware1.1.0.7Not stated
SharpPn-l703wa Firmware1.4.2.3Not stated
OptomaWps-pro Firmware1.0.0.5Not stated
BlackboxHd Wireless Presentation System Firmware1.0.0.5Not stated
InfocusLiteshow3 Firmware1.0.16Not stated
InfocusLiteshow4 Firmware2.0.0.7Not 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 NVD.

Scoring systemScoreSeverityScored by
CVSS 3.19.8CriticalNVD
CVSS 3.19.8CriticalCISA (ADP)
CVSS 2.010.0HighNVD

Official description

The Crestron AM-100 firmware 1.6.0.2, Crestron AM-101 firmware 2.7.0.1, Barco wePresent WiPG-1000P firmware 2.3.0.10, Barco wePresent WiPG-1600W before firmware 2.4.1.19, Extron ShareLink 200/250 firmware 2.0.3.4, Teq AV IT WIPS710 firmware 1.1.0.7, SHARP PN-L703WA firmware 1.4.2.3, Optoma WPS-Pro firmware 1.0.0.5, Blackbox HD WPS firmware 1.0.0.5, InFocus LiteShow3 firmware 1.0.16, and InFocus LiteShow4 2.0.0.7 are vulnerable to command injection via the file_transfer.cgi HTTP endpoint. A remote, unauthenticated attacker can use this vulnerability to execute operating system commands as root.

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

The underlying weakness: Improper Neutralization of Special Elements used in an OS Command

The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command before it is sent to a downstream component.

How developers prevent this class of flaw

  • If at all possible, use library calls rather than external processes to recreate the desired functionality.
  • For any data that will be used to generate a command to be executed, keep as much of that data out of external control as possible. For example, in web applications, this may require storing the data locally in the session's state instead of sending it out to the client in a hidden form field.
  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

More Improper Neutralization of Special Elements used in an OS Command vulnerabilities (CWE-78)

Timeline

  1. CVE record published.
  2. Added to CISA's Known Exploited Vulnerabilities catalogue.
  3. Deadline for US federal agencies to remediate, set by CISA.
  4. CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: total).
  5. Record last changed materially (score, affected products, status or references).

References

Technical write-ups (may include proof of concept)

Recent Improper Neutralization of Special Elements used in an OS Command vulnerabilities

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