Cyber Resilience

CVE-2023-20078

Memory Safety in Cisco Ip Phone 6871 Firmware ≤ 11.3.7sr1

Memory Safety
Published
03 March 2023
Modified
21 November 2024
Patch / advisory
View 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 95th percentile
Risk Priority 84 floored blend · peak EPSS

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 Exploitation for Privilege Escalation (T1068); ranked in the top 5% 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)
CWE-121CWE-787

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
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-2025-20350Same product: Cisco Ip Phone 7811
CVE-2022-20701Same vendor: Cisco
CVE-2024-20520Same vendor: Cisco
CVE-2024-20524Same vendor: Cisco
CVE-2024-20433Same vendor: Cisco
CVE-2024-20519Same vendor: Cisco
CVE-2024-20523Same vendor: Cisco
CVE-2024-20521Same vendor: Cisco
CVE-2022-20707Same 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.

SI-16 Memory Protection
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.

PR.PS-06 mostly match
prevents

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

ID.RA-01 partial match
prevents

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

PR.PS-02 partial match
prevents

Patching eliminates known instances of the weakness after discovery.

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.8.29 Security testing in development and acceptance mostly match
finds

Security testing (fuzzing, static analysis) detects stack overflows before release.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates buffer-safety practices that directly prevent stack overflows.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify buffer-size and input-validation rules.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles include memory-safety and least-privilege stack usage.

A.8.28 Secure coding partial match
prevents

Secure coding standards explicitly forbid unsafe buffer handling that causes CWE-121.

A.8.32 Change management partial match
prevents

Change management can enforce review gates that catch unsafe memory operations before deployment.

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` (authoritative 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. prevents CWE-121
Oracle Linux 9 (1 rule)
  • V-271452 OL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-121

References