CVE-2021-22811 in NMC2 AOS
Summary
by MITRE • 01/28/2022
A CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability exists that could cause script execution when the request of a privileged account accessing the vulnerable web page is intercepted. Affected Products: 1-Phase Uninterruptible Power Supply (UPS) using NMC2 including Smart-UPS, Symmetra, and Galaxy 3500 with Network Management Card 2 (NMC2): AP9630/AP9630CH/AP9630J, AP9631/AP9631CH/AP9631J, AP9635/AP9635J (NMC2 AOS V6.9.8 and earlier), 3-Phase Uninterruptible Power Supply (UPS) using NMC2 including Symmetra PX 250/500 (SYPX) Network Management Card 2 (NMC2): AP9630/AP9630CH/AP9630J, AP9631/AP9631CH/AP9631J, AP9635/AP9635J (NMC2 AOS V6.9.6 and earlier), 3-Phase Uninterruptible Power Supply (UPS) using NMC2 including Symmetra PX 48/96/100/160 kW UPS (PX2), Symmetra PX 20/40 kW UPS (SY3P), Gutor (SXW, GVX), and Galaxy (GVMTS, GVMSA, GVXTS, GVXSA, G7K, GFC, G9KCHU): AP9630/AP9630CH/AP9630J, AP9631/AP9631CH/AP9631J, AP9635/AP9635CH (NMC2 AOS V6.9.6 and earlier), 1-Phase Uninterruptible Power Supply (UPS) using NMC3 including Smart-UPS, Symmetra, and Galaxy 3500 with Network Management Card 3 (NMC3): AP9640/AP9640J, AP9641/AP9641J, AP9643/AP9643J (NMC3 AOS V1.4.2.1 and earlier), APC Rack Power Distribution Units (PDU) using NMC2 2G Metered/Switched Rack PDUs with embedded NMC2: AP84XX, AP86XX, AP88XX, AP89XX (NMC2 AOS V6.9.6 and earlier), APC Rack Power Distribution Units (PDU) using NMC3 2G Metered/Switched Rack PDUs with embedded NMC3: APDU99xx (NMC3 AOS V1.4.0 and earlier), APC 3-Phase Power Distribution Products using NMC2 Galaxy RPP: GRPPIP2X84 (NMC2 AOS V6.9.6 and earlier), Network Management Card 2 (NMC2) for InfraStruxure 150 kVA PDU with 84 Poles (X84P): PDPB150G6F (NMC2 AOS V6.9.6 and earlier), Network Management Card 2 for InfraStruxure 40/60kVA PDU (XPDU) PD40G6FK1-M, PD40F6FK1-M, PD40L6FK1-M, PDRPPNX10 M,PD60G6FK1, PD60F6FK1, PD60L6FK1, PDRPPNX10, PD40E5EK20-M, PD40H5EK20-M (NMC2 AOS V6.9.6 and earlier), Network Management Card 2 for Modular 150/175kVA PDU (XRDP): PDPM150G6F, PDPM150L6F, PDPM175G6H (NMC2 AOS V6.9.6 and earlier), Network Management Card 2 for 400 and 500 kVA (PMM): PMM400-ALA, PMM400-ALAX, PMM400-CUB, PMM500-ALA, PMM500-ALAX, PMM500-CUB (NMC2 AOS V6.9.6 and earlier), Network Management Card 2 for Modular PDU (XRDP2G): PDPM72F-5U, PDPM138H-5U, PDPM144F, PDPM138H-R, PDPM277H, PDPM288G6H (NMC2 AOS V6.9.6 and earlier), Rack Automatic Transfer Switches (ATS) Embedded NMC2: Rack Automatic Transfer Switches - AP44XX (ATS4G) (NMC2 AOS V6.9.6 and earlier), Network Management Card 2 (NMC2) Cooling Products: InRow Cooling for series ACRP5xx, ACRP1xx, ACRD5xx, and ACRC5xx SKUs (ACRP2G), InRow Cooling for series ACRC10x SKUs (RC10X2G), InRow Cooling for series ACRD6xx and ACRC6xx SKUs (ACRD2G), InRow Cooling Display for series ACRD3xx (ACRC2G), InRow Cooling for series ACSC1xx SKUs (SC2G), InRow Cooling for series ACRD1xx and ACRD2xx (ACRPTK2G), Ecoflair IAEC25/50 Air Economizer Display (EB2G), Uniflair SP UCF0481I, UCF0341I (UNFLRSP), Uniflair LE DX Perimeter Cooling Display for SKUs: IDAV, IDEV, IDWV, IUAV, IUEV, IUWV, IXAV, IXEV, IXWV, LDAV, LDEV, and LDWV (LEDX2G), Refrigerant Distribution Unit: ACDA9xx (RDU) (NMC2 AOS V6.9.6 and earlier), Environmental Monitoring Unit with embedded NMC2 (NB250): NetBotz NBRK0250 (NMC2 AOS V6.9.6 and earlier), and Network Management Card 2 (NMC2): AP9922 Battery Management System (BM4) (NMC2 AOS V6.9.6 and earlier)
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Analysis
by VulDB Data Team • 01/28/2022
This vulnerability represents a classic cross-site scripting flaw classified under CWE-79 that affects numerous APC network management cards across various power distribution and cooling equipment. The weakness occurs during web page generation when input data is not properly sanitized before being rendered in HTML output, creating opportunities for malicious scripts to execute within the context of privileged user sessions. Attackers can exploit this vulnerability by intercepting requests from authenticated users accessing vulnerable web interfaces, enabling them to inject and execute arbitrary JavaScript code in the victim's browser.
The affected devices span multiple product lines including 1-phase and 3-phase uninterruptible power supplies, rack power distribution units, cooling systems, and environmental monitoring equipment. Specific impacted models include Smart-UPS, Symmetra, Galaxy 3500 series with NMC2 versions through V6.9.8, as well as various Symmetra PX models and related NMC3 implementations. The vulnerability affects both Network Management Cards 2 and 3 across different hardware platforms, with particular emphasis on older firmware versions where the input sanitization mechanisms fail to properly neutralize malicious payloads.
The operational impact of this vulnerability is significant for organizations relying on these devices, as it allows attackers to potentially escalate privileges and gain unauthorized access to critical infrastructure management interfaces. When a privileged user accesses a vulnerable web page, the injected scripts can execute with the user's administrative rights, potentially leading to full system compromise, data exfiltration, or disruption of power distribution services. This risk is exacerbated by the fact that these devices typically operate in enterprise environments where they may be accessible from untrusted networks or where network segmentation is insufficient.
Security professionals should implement immediate mitigations including firmware updates to the latest available versions that address the XSS vulnerability through proper input validation and output encoding mechanisms. Network segmentation and access controls should be strengthened to limit direct web access to these management interfaces, while implementing secure network protocols such as HTTPS with strong encryption. The vulnerability aligns with ATT&CK technique T1059.007 for script execution and T1566 for credential harvesting through web-based attacks, emphasizing the need for comprehensive defensive measures including web application firewalls and regular security assessments of industrial control systems. Organizations should also consider implementing network monitoring to detect suspicious traffic patterns associated with XSS payload delivery and maintain detailed logs of management interface access for forensic analysis.