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Fencer Vulns
high 7.4

CVE-2021-1352 json

Cisco IOS XE Software DECnet Phase IV/OSI Denial of Service Vulnerability

published 2021-03-24 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-6819

cvss
7.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 36%
public exploits
0
none known

Summary

A vulnerability in the DECnet Phase IV and DECnet/OSI protocol processing of Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient input validation of DECnet traffic that is received by an affected device. An attacker could exploit this vulnerability by sending DECnet traffic to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-21-110-02 updated cvss 7.0

ICSA-21-110-02_Rockwell Automation Stratix Switches

  • Rockwell Automation Stratix 5400 <= 15.2(7)E3 Rockwell Automation Stratix 5410 <= 15.2(7)E3 Rockwell Automation Stratix 5700 <= 15.2(7)E3 Rockwell Automation Stratix 5800 <= 16.12.01 Rockwell Automation Stratix 8000 <= 15.2(7)E3
    affected: vendor fix, mitigation “Rockwell Automation encourages users of the affected Stratix devices to update to an available firmware revision that addresses the associated risk.” rockwellautomation.custhelp.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.42% chance of exploitation in the next 30 days, higher than 36% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.4 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
NVD 3.1 6.5 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 2.9 AV:A/AC:M/Au:N/C:N/I:N/A:P

Affected products

  • Cisco Cisco IOS XE Software

Classification

Weakness
  • CWE-823 Use of Out-of-range Pointer Offset
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.