Security Resilience

CVE-2023-20078

Memory Safety in Cisco Ip Phone 6871 Firmware ≤ 11.3.7sr1

Published
03 March 2023
Modified
21 November 2024
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.10 96th percentile
Risk Priority 84 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-2023-20078 is a critical-severity Stack-based Buffer Overflow (CWE-121) vulnerability in Cisco Ip Phone 6871 Firmware. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Security Account Manager (T1003.002); ranked in the top 4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

Multiple vulnerabilities affect the web-based management interface of certain Cisco IP Phones, with the issues rooted in stack-based buffer overflows and out-of-bounds writes as indicated by the associated CWEs. These flaws enable unauthenticated remote attackers to trigger arbitrary code execution or denial-of-service conditions on the affected devices, reflected in the critical CVSS 9.8 score with network attack vector and no required privileges or user interaction.

An unauthenticated remote attacker can send specially crafted requests to the exposed web interface to achieve full code execution or crash the phone, compromising both confidentiality and availability without any prior authentication.

The official Cisco Security Advisory at the referenced URL details the affected phone models and available software updates that address the command injection and memory safety issues. The EPSS score rose materially from low values after disclosure to a peak of 0.2010 on 2025-12-11 before receding, indicating that exploitation interest emerged well after the initial publication and warrants renewed attention.

EU & UK References

Vulnerability Data

Multiple vulnerabilities in the web-based management interface of certain Cisco IP Phones could allow an unauthenticated, remote attacker to execute arbitrary code or cause a denial of service (DoS) condition. For more information about these vulnerabilities, see the Details section…

more

of this advisory.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1003.002 Security Account Manager Credential Access
Adversaries may attempt to extract credential material from the Security Account Manager (SAM) database either through in-memory techniques or through the Windows Registry where the SAM database is stored.
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.
T1003.008 /etc/passwd and /etc/shadow Credential Access
Adversaries may attempt to dump the contents of <code>/etc/passwd</code> and <code>/etc/shadow</code> to enable offline password cracking.
T1006 Direct Volume Access Stealth
Adversaries may directly access a volume to bypass file access controls and file system monitoring.
T1007 System Service Discovery Discovery
Adversaries may try to gather information about registered local system services.
T1012 Query Registry Discovery
Adversaries may interact with the Windows Registry to gather information about the system, configuration, and installed software.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-20079Same product: Cisco Ip Phone 6825
CVE-2024-20376Same product: Cisco Ip Phone 6841
CVE-2024-20357Same product: Cisco Ip Phone 6841
CVE-2022-20701Same vendor: Cisco
CVE-2023-20250Same vendor: Cisco
CVE-2022-20707Same vendor: Cisco
CVE-2024-20519Same vendor: Cisco
CVE-2024-20524Same vendor: Cisco
CVE-2024-20520Same vendor: Cisco
CVE-2022-20700Same vendor: Cisco

Affected Assets

cisco
ip phone 6871 firmware
≤ 11.3.7sr1
cisco
ip phone 6861 firmware
≤ 11.3.7sr1
cisco
ip phone 6851 firmware
≤ 11.3.7sr1
cisco
ip phone 6841 firmware
≤ 11.3.7sr1
cisco
ip phone 6825 firmware
≤ 11.3.7sr1
cisco
ip phone 7861 firmware
≤ 11.3.7sr1
cisco
ip phone 7841 firmware
≤ 11.3.7sr1
cisco
ip phone 7832 firmware
≤ 11.3.7sr1
cisco
ip phone 7821 firmware
≤ 11.3.7sr1
cisco
ip phone 7811 firmware
≤ 11.3.7sr1
+7 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)
  • 2 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)

—

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-787

Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.

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.

ID.RA-01 partial match
blocks

Vulnerability scanning can discover stack buffer overflows but does not prevent their introduction.

PR.PS-02 partial match
blocks

Patching eliminates known instances of the weakness after discovery.

PR.PS-06 partial match
blocks

Secure-development practices directly prevent introduction of stack buffer overflows.

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.

removes
removes
removes
removes
removes

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (higher-evidence rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248594 OL 8 must implement address space layout randomization (ASLR) to protect its memory from unauthorized code execution. blocks CWE-121
Oracle Linux 9 (1 rule)
  • V-271452 OL 9 must use a Linux Security Module configured to enforce limits on system services. blocks CWE-121

References