Security Resilience

CVE-2024-20534

XSS in Cisco Video Phone 8875 With Multiplatform Firmware ≤ 2.3\(1\)

XSS
Published
06 November 2024
Modified
05 January 2026
Patch / advisory
View advisory
CVSS Score v3.1 4.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.0029 21th percentile
Risk Priority 33 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2024-20534 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Cisco Video Phone 8875 With Multiplatform Firmware. Its CVSS base score is 4.8 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Protocol or Service Impersonation (T1001.003); ranked at the 21th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

A vulnerability in the web UI of Cisco Desk Phone 9800 Series, Cisco IP Phone 6800, 7800, and 8800 Series, and Cisco Video Phone 8875 with Cisco Multiplatform Firmware could allow an authenticated, remote attacker to conduct stored cross-site scripting…

more

(XSS) attacks against users. This vulnerability exists because the web UI of an affected device does not properly validate user-supplied input. An attacker could exploit this vulnerability by injecting malicious code into specific pages of the interface. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive, browser-based information. Note: To exploit this vulnerability, Web Access must be enabled on the phone and the attacker must have Admin credentials on the device. Web Access is disabled by default.

CWE(s)
CWE-79

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001.003 Protocol or Service Impersonation Command And Control
Adversaries may impersonate legitimate protocols or web service traffic to disguise command and control activity and thwart analysis efforts.
attack.mitre.org →
T1003.004 LSA Secrets Credential Access
Adversaries with SYSTEM access to a host may attempt to access Local Security Authority (LSA) secrets, which can contain a variety of different credential materials, such as credentials for service accounts.
attack.mitre.org →
T1003.005 Cached Domain Credentials Credential Access
Adversaries may attempt to access cached domain credentials used to allow authentication to occur in the event a domain controller is unavailable.
attack.mitre.org →
T1007 System Service Discovery Discovery
Adversaries may try to gather information about registered local system services.
attack.mitre.org →
T1011 Exfiltration Over Other Network Medium Exfiltration
Adversaries may attempt to exfiltrate data over a different network medium than the command and control channel.
attack.mitre.org →
T1012 Query Registry Discovery
Adversaries may interact with the Windows Registry to gather information about the system, configuration, and installed software.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-20144Same vendor: Cisco
CVE-2023-20068Same vendor: Cisco
CVE-2023-20203Same vendor: Cisco
CVE-2023-20148Same vendor: Cisco
CVE-2023-20205Same vendor: Cisco
CVE-2023-20085Same vendor: Cisco
CVE-2023-20204Same vendor: Cisco
CVE-2023-20143Same vendor: Cisco
CVE-2023-20119Same vendor: Cisco
CVE-2023-20206Same vendor: Cisco

Affected Assets

cisco
desk phone 9841 with multiplatform firmware
3.1\(1\)
cisco
desk phone 9851 with multiplatform firmware
3.1\(1\)
cisco
desk phone 9861 with multiplatform firmware
3.1\(1\)
cisco
desk phone 9871 with multiplatform firmware
3.1\(1\)
cisco
ip phone 6821 with multiplatform firmware
12.0\(5\)
cisco
ip phone 6841 with multiplatform firmware
12.0\(5\)
cisco
ip phone 6851 with multiplatform firmware
12.0\(5\)
cisco
ip phone 6861 with multiplatform firmware
12.0\(5\)
cisco
ip phone 6871 with multiplatform firmware
12.0\(5\)
cisco
ip phone 7811 with multiplatform firmware
12.0\(5\)
+13 more product configuration(s) — see NVD for full list

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.1.2
  • V1.3.2

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover missing or incorrect input neutralization through targeted web-application tests.

SI-10 Information Input Validation good match

Input validation directly enforces neutralization of untrusted data before it reaches web output generation.

SI-15 Information Output Filtering good match

Output filtering can catch or sanitize unneutralized script content before it is served to users.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
blocks

Secure SDLC practices directly target introduction of XSS via coding standards/testing (mostly), yet the single broad outcome leaves many specific neutralization vectors unaddressed (partial).

PR.PS-02 partial match
blocks

Patching and EOL replacement can remediate known XSS instances in libraries or frameworks (partial) but do nothing to enforce input neutralization in application code (none).

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.5.6 Contact with special interest groups partial match
blocks

A.5.6 only promotes membership in groups to improve knowledge, receive alerts, and share information; it performs no action that stops XSS exploitation (or even the underlying neutralization defect) and is a pure dependency for other controls per the owner's labeling rule.

References