CyberSecBulletin
CVE-2019-1579Exploited in the wildNVD status: Analyzed

Palo Alto Networks PAN-OS Remote Code Execution

Published Updated By the CyberSecBulletin desk

CVE-2019-1579 is a high-severity use of externally-controlled format string vulnerability in Palo Alto Networks GlobalProtect Portal/Gateway Interface, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. CISA added it to the Known Exploited Vulnerabilities catalogue on January 10, 2022, which means attacks have been observed in the wild, including in ransomware campaigns.

Patch now

Attackers are already exploiting this vulnerability, according to CISA.

What to do

  1. Update Pan-os to 7.1.19 or 8.0.12 or 8.1.3, whichever matches your release line, or a later version.
  2. CISA's required action: Apply updates per vendor instructions.
  3. Read the advisory on security.paloaltonetworks.com for workarounds and exact fixed builds.
  4. 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
Palo Alto Networks GlobalProtect Portal/Gateway InterfacePalo Alto Networks GlobalProtect Portal/Gateway InterfaceNot specified in the recordNot stated
Palo Alto NetworksPan-osbefore 7.1.19; 8.0.0 up to, but not including, 8.0.12; 8.1.0 up to, but not including, 8.1.37.1.19, 8.0.12, 8.1.3

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
HighSuccess depends on conditions outside the attacker's control.
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:H/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.1HighNVD
CVSS 3.18.1HighCISA (ADP)
CVSS 2.06.8MediumNVD

Official description

Remote Code Execution in PAN-OS 7.1.18 and earlier, PAN-OS 8.0.11-h1 and earlier, and PAN-OS 8.1.2 and earlier with GlobalProtect Portal or GlobalProtect Gateway Interface enabled may allow an unauthenticated remote attacker to execute arbitrary code.

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

The underlying weakness: Use of Externally-Controlled Format String

The product uses a function that accepts a format string as an argument, but the format string originates from an external source.

How developers prevent this class of flaw

  • Choose a language that is not subject to this flaw.
  • Ensure that all format string functions are passed a static string which cannot be controlled by the user, and that the proper number of arguments are always sent to that function as well. If at all possible, use functions that do not support the %n operator in format strings.
  • Run compilers and linkers with high warning levels, since they may detect incorrect usage.

More Use of Externally-Controlled Format String vulnerabilities (CWE-134)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
  3. Added to CISA's Known Exploited Vulnerabilities catalogue.
  4. Deadline for US federal agencies to remediate, set by CISA.
  5. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Technical write-ups (may include proof of concept)

Recent Use of Externally-Controlled Format String vulnerabilities

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