Skip to main content

Ios Xe CVE-2024-20309

MEDIUM
Signal Handler with Functionality that is not Asynchronous-Safe (CWE-828)
2024-03-27 psirt@cisco.com
5.5
CVSS 3.1 · NVD
View

Vulnerability Assessment

Weakness
CWE
Impact

CVSS score of 5.5 (MEDIUM). Attack characteristics: local attack vector, low complexity, low privileges required, no user interaction not required.

Exploit ScenarioDerived

Successful exploitation could compromise the medium-severity affected system.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
No patch listed yet 0.1% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAI

A vulnerability in auxiliary asynchronous port (AUX) functions of Cisco IOS XE Software could allow an authenticated, local attacker to cause an affected device to reload or stop responding. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified under CWE-828. A vulnerability in auxiliary asynchronous port (AUX) functions of Cisco IOS XE Software could allow an authenticated, local attacker to cause an affected device to reload or stop responding. This vulnerability is due to the incorrect handling of specific ingress traffic when flow control hardware is enabled on the AUX port. An attacker could exploit this vulnerability by reverse telnetting to the AUX port and sending specific data after connecting. A successful exploit could allow the attacker to cause the device to reset or stop responding, resulting in a denial of service (DoS) condition. Affected products include: Cisco Ios Xe.

Know when Ios Xe gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

NVD PRIMARY 5.5 MEDIUM
AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

DescriptionNVD

A vulnerability in auxiliary asynchronous port (AUX) functions of Cisco IOS XE Software could allow an authenticated, local attacker to cause an affected device to reload or stop responding. This vulnerability is due to the incorrect handling of specific ingress traffic when flow control hardware is enabled on the AUX port. An attacker could exploit this vulnerability by reverse telnetting to the AUX port and sending specific data after connecting. A successful exploit could allow the attacker to cause the device to reset or stop responding, resulting in a denial of service (DoS) condition.

Threat Intelligence Overview

EPSS Score
0.1%
Top 99% exploitable
Data Quality
2 sources
Confidence: Low

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC No
EPSS 0.1%
Patch available No
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Defer
Exploitation· derived
None
System Exposure· derived
Small
Automatable· derived
No
Human Impact· derived
Medium

Priority Score

28
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +28
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.

Affected Products (CPE)NVD

cpe:2.3:o:cisco:ios_xe:3.2.0se:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.2.1se:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.2.2se:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.2.3se:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.3.0se:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.3.0sq:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.3.1se:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.3.1sq:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.3.2se:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.3.3se:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.3.4se:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.3.5se:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.4.0sq:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.4.1sq:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.5.0sq:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.5.1sq:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.5.2sq:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.5.3sq:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.5.4sq:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.5.5sq:*:*:*:*:*:*:*
+ 323 more

More in Ios Xe

View all
CVE-2023-44487 HIGH POC
7.5 Oct 10

Denial of service against HTTP/2 server implementations allows remote unauthenticated attackers to exhaust server resour

CVE-2017-6739 HIGH
8.8 Jul 17

A vulnerability in the SNMP implementation of could allow an authenticated, remote attacker to cause a reload of the aff

CVE-2017-6737 HIGH
8.8 Jul 17

A vulnerability in the SNMP implementation of could allow an authenticated, remote attacker to cause a reload of the aff

CVE-2017-6742 HIGH
8.8 Jul 17

A vulnerability in the SNMP implementation of could allow an authenticated, remote attacker to cause a reload of the aff

CVE-2025-20352 HIGH
7.7 Sep 24

A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software and Cisco IOS XE Softwa

CVE-2023-20198 CRITICAL POC
10.0 Oct 16

Cisco is providing an update for the ongoing investigation into observed exploitation of the web UI feature in Cisco IOS

CVE-2025-20188 CRITICAL POC
10.0 May 07

A vulnerability in the Out-of-Band Access Point (AP) Image Download, the Clean Air Spectral Recording, and the client de

CVE-2023-20273 HIGH POC
7.2 Oct 25

A vulnerability in the web UI feature of Cisco IOS XE Software could allow an authenticated, remote attacker to inject c

CVE-2017-12229 CRITICAL
9.8 Sep 29

A vulnerability in the REST API of the web-based user interface (web UI) of Cisco IOS XE 3.1 through 16.5 could allow an

CVE-2022-20723 HIGH POC
7.2 Apr 15

Multiple vulnerabilities in the Cisco IOx application hosting environment on multiple Cisco platforms could allow an att

CVE-2022-20719 HIGH POC
7.2 Apr 15

Multiple vulnerabilities in the Cisco IOx application hosting environment on multiple Cisco platforms could allow an att

CVE-2022-20718 HIGH POC
7.2 Apr 15

Multiple vulnerabilities in the Cisco IOx application hosting environment on multiple Cisco platforms could allow an att

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy