Cyber Resilience

CVE-2023-20177

Cisco Secure Firewall Threat Defense 7.0.0 … 7.3.1.1

Published
01 November 2023
Modified
11 August 2026
Patch / advisory
View advisory
CVSS Score v3.1 4.0
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:L
EPSS Score 0.0053 42th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2023-20177 is a medium-severity Heap Inspection (CWE-244) vulnerability in Cisco Secure Firewall Threat Defense. Its CVSS base score is 4.0 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique OS Credential Dumping (T1003); ranked at the 42th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability Data

A vulnerability in the SSL file policy implementation of Cisco Firepower Threat Defense (FTD) Software that occurs when the SSL/TLS connection is configured with a URL Category and the Snort 3 detection engine could allow an unauthenticated, remote attacker to…

more

cause the Snort 3 detection engine to unexpectedly restart. This vulnerability exists because a logic error occurs when a Snort 3 detection engine inspects an SSL/TLS connection that has either a URL Category configured on the SSL file policy or a URL Category configured on an access control policy with TLS server identity discovery enabled. Under specific, time-based constraints, an attacker could exploit this vulnerability by sending a crafted SSL/TLS connection through an affected device. A successful exploit could allow the attacker to trigger an unexpected reload of the Snort 3 detection engine, resulting in either a bypass or denial of service (DoS) condition, depending on device configuration. The Snort 3 detection engine will restart automatically. No manual intervention is required.

CWE(s)
CWE-244NVD-CWE-noinfo

Related Threats

MITRE ATT&CK Enterprise Techniques

T1003 OS Credential Dumping Credential Access
Adversaries may attempt to dump credentials to obtain account login and credential material, normally in the form of a hash or a clear text password.
attack.mitre.org →
T1552 Unsecured Credentials Credential Access
Adversaries may search compromised systems to find and obtain insecurely stored credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-20031Same product: Cisco Secure Firewall Threat Defense
CVE-2023-20070Same product: Cisco Secure Firewall Threat Defense
CVE-2026-20039Same product: Cisco Secure Firewall Threat Defense
CVE-2026-20349Same product: Cisco Secure Firewall Threat Defense
CVE-2023-20083Same product: Cisco Secure Firewall Threat Defense
CVE-2023-20267Same product: Cisco Secure Firewall Threat Defense
CVE-2024-20351Same product: Cisco Secure Firewall Threat Defense
CVE-2026-20017Same product: Cisco Secure Firewall Threat Defense
CVE-2024-20431Same product: Cisco Secure Firewall Threat Defense
CVE-2023-20270Same product: Cisco Secure Firewall Threat Defense

Affected Assets

cisco
secure firewall threat defense
7.0.0, 7.0.0.1, 7.0.1, 7.0.1.1, 7.0.2

Mitigating Controls

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.

SC-4 Information in Shared System Resources
addresses: CWE-244

Forces clearing of heap memory contents prior to release, preventing subsequent processes from inspecting prior sensitive data.

SI-12 Information Management and Retention
addresses: CWE-244

Information management requirements drive clearing of sensitive contents from memory prior to release or reuse.

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.DS-10 mostly match
prevents

Explicit example of removing confidential data from process memory directly prevents heap inspection exposure.

PR.PS-06 partial match
prevents

Secure SDLC practices encompass proper sensitive-memory handling but fixing this single CWE does not achieve the control.

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.8.10 Information deletion partial match
prevents

Explicitly requires secure deletion of sensitive data, directly addressing improper heap clearing.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC processes can incorporate memory-safety requirements but do not specifically mandate heap clearing.

A.8.28 Secure coding partial match
prevents

Mandates secure coding practices that include proper memory sanitization before release.

A.8.27 Secure system architecture and engineering principles none match
none

Secure architecture principles may reduce exposure but do not prescribe explicit heap-clearing techniques.

References