Cisco IOS XE SD-WAN Software Arbitrary File Overwrite Vulnerability

published 2021-09-23 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-7079

cvss: 5.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 16%
public exploits: 0; none known

A vulnerability in the Cisco IOS XE SD-WAN Software CLI could allow an authenticated, local attacker to overwrite arbitrary files on the local system. This vulnerability is due to improper access controls on files within the local file system. An attacker could exploit this vulnerability by placing a symbolic link in a specific location on the local file system. A successful exploit could allow the attacker to overwrite arbitrary files on an affected device.

Patch / fix

fixed in 1 links 1

cisco sd-wan 17.3.4

tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sd-… advisory

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 y ago (2024-11-07)

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 16% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
NVD	3.1	7.1	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
NVD	2.0	6.6	AV:L/AC:L/Au:N/C:N/I:C/A:C

Affected products

Cisco Cisco IOS XE SD-WAN Software

Classification

Weakness

CWE-61 UNIX Symbolic Link (Symlink) Following
CWE-59 Improper Link Resolution Before File Access

References

tools.cisco.com /security/center/content/CiscoSecurityAdvisory/cisco-sa-sd-wan-GjR5pGOm
vendor-advisory, patch

Sources

CVE List CVE-2021-1612
NVD CVE-2021-1612

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Summary