CVE-2024-20271 [High] | Input Validation Bypass in Ios Xe

A vulnerability in the IP packet processing of Cisco Access Point (AP) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient input validation of certain IPv4 packets. An attacker could exploit this vulnerability by sending a crafted IPv4 packet either to or through an affected device. A successful exploit could allow the attacker to cause an affected device to reload unexpectedly, resulting in a DoS condition. To successfully exploit this vulnerability, the attacker does not need to be associated with the affected AP. This vulnerability cannot be exploited by sending IPv6 packets.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.32%	0.63%	+0.31%
2	2026-03-16	0.42%	0.32%	-0.10%
3	2025-12-28	—	0.42%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.32%

0.63%

+0.31%

2026-03-16

0.42%

0.32%

-0.10%

2025-12-28

—

0.42%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
8.6	3.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	4.0	[email protected]
8.6	3.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	4.0	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

8.6

3.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

4.0

[email protected]

8.6

3.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

4.0

[email protected]

Affected software / configurations for CVE-2024-20271

Vendor	Product	Version	Raw CPE
cisco	ios_xe	< 17.3.8	cpe:2.3:o:cisco:ios_xe::::::::
cisco	ios_xe	>= 17.4, < 17.6.6	cpe:2.3:o:cisco:ios_xe::::::::
cisco	ios_xe	>= 17.7, < 17.9.5	cpe:2.3:o:cisco:ios_xe::::::::
cisco	ios_xe	>= 17.10, < 17.12.2	cpe:2.3:o:cisco:ios_xe::::::::
cisco	business_access_points	< 10.9.1.0	cpe:2.3:a:cisco:business_access_points::::::::
cisco	business_access_points	< 10.6.2.0	cpe:2.3:a:cisco:business_access_points::::::::
cisco	wireless_lan_controller_software	< 8.10.190.0	cpe:2.3:o:cisco:wireless_lan_controller_software::::::::

References for CVE-2024-20271

URL	Tags
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ap-dos-h9TGGX6W	Vendor Advisory

URL

CVE-2024-20271

Exploit prediction scoring system (EPSS) score for CVE-2024-20271

Common vulnerability scoring system (CVSS) metrics for CVE-2024-20271

Weakness enumeration for CVE-2024-20271

Affected software / configurations for CVE-2024-20271

References for CVE-2024-20271