// For flags

CVE-2021-1616

Cisco IOS XE Software H.323 Application Level Gateway Bypass Vulnerability

Severity Score

4.7
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

A vulnerability in the H.323 application level gateway (ALG) used by the Network Address Translation (NAT) feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to bypass the ALG. This vulnerability is due to insufficient data validation of traffic that is traversing the ALG. An attacker could exploit this vulnerability by sending crafted traffic to a targeted device. A successful exploit could allow the attacker to bypass the ALG and open connections that should not be allowed to a remote device located behind the ALG. Note: This vulnerability has been publicly discussed as NAT Slipstreaming.

Una vulnerabilidad en el gateway de nivel de aplicación H.323 (ALG) usada por la funcionalidad Network Address Translation (NAT) de Cisco IOS XE Software podría permitir a un atacante remoto no autenticado omitir la ALG. Esta vulnerabilidad es debido a una comprobación insuficiente de los datos del tráfico que atraviesa el ALG. Un atacante podría explotar esta vulnerabilidad mediante el envío de tráfico diseñado a un dispositivo objetivo. Una explotación con éxito podría permitir al atacante omitir el ALG y abrir conexiones que no deberían estar permitidas a un dispositivo remoto ubicado detrás del ALG. Nota: Esta vulnerabilidad ha sido discutida públicamente como NAT Slipstreaming

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Changed
Confidentiality
None
Integrity
Low
Availability
None
Attack Vector
Network
Attack Complexity
Medium
Authentication
None
Confidentiality
None
Integrity
Partial
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2020-11-13 CVE Reserved
  • 2021-09-23 CVE Published
  • 2024-04-28 EPSS Updated
  • 2024-11-07 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-693: Protection Mechanism Failure
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
< 17.6.1
Search vendor "Cisco" for product "Ios Xe" and version " < 17.6.1"
-
Affected