Security readout for executives and security teams
Plain-English summary
This vulnerability can let an unauthenticated attacker crash Palo Alto Networks PAN-OS firewall services by sending crafted traffic through the firewall. Repeated triggering can restart the device and place it into maintenance mode, creating a business-impacting outage risk for affected firewall deployments.
Executive priority
Treat as a high-priority availability risk for affected perimeter and internal firewalls. It does not indicate data theft or privilege escalation, but firewall outage can disrupt internet access, VPN, segmentation, and business operations.
Technical view
CVE-2021-3053 is an improper exceptional-condition handling flaw in the PAN-OS dataplane. The CVSS 3.1 score is 7.5, with network attack vector, low complexity, no privileges, no user interaction, and high availability impact. Prisma Access is stated as unaffected.
Likely exposure
Exposure is most likely where Palo Alto Networks PAN-OS firewalls run vulnerable releases: 8.1 before 8.1.20, 9.0 before 9.0.14, 9.1 before 9.1.9, or 10.0 before 10.0.5. The structured source data also lists 10.1.*, so confirm exact applicability against the vendor advisory.
Exploitation context
The bundle describes unauthenticated network-based denial of service through crafted traffic sent through the firewall. It does not cite CISA KEV listing or any public evidence of active exploitation, so active exploitation should not be assumed from these sources.
Researcher notes
The public details identify impact and fixed version thresholds but do not provide protocol, traffic pattern, or exploit indicators. The affected-product metadata includes PAN-OS 10.1.*, while the narrative affected list stops at 10.0; verify against Palo Alto Networks’ advisory before scoping 10.1.
Mitigation direction
- Upgrade PAN-OS 8.1 deployments to 8.1.20 or later.
- Upgrade PAN-OS 9.0 deployments to 9.0.14 or later.
- Upgrade PAN-OS 9.1 deployments to 9.1.9 or later.
- Upgrade PAN-OS 10.0 deployments to 10.0.5 or later.
- Check Palo Alto Networks guidance for any 10.1 applicability or platform-specific notes.
Validation and detection
- Inventory Palo Alto Networks firewalls and record PAN-OS versions.
- Compare each version against the affected version thresholds in the advisory.
- Confirm Prisma Access assets are not counted as affected.
- Review firewall availability incidents for unexplained dataplane crashes or maintenance-mode restarts.
- Track remediation status for every vulnerable firewall until upgraded.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-755: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-3053 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://security.paloaltonetworks.com/CVE-2021-3053CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Handling of Exceptional Conditions
Improper Handling of Exceptional Conditions represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.