CVE-2021-27189: The CIRA Canadian Shield app before 4.0.13 for iOS lacks SSL Certificate Validation.

Q: How do I fix CVE-2021-27189?

canadian shield: upgrade to 4.0.13. Exact commands for each OS are on this page.

Q: Is CVE-2021-27189 being exploited?

CVE-2021-27189 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-27189 affect?

CVE-2021-27189 affects canadian shield. Severity is medium (CVSS 5.9). The CIRA Canadian Shield app before 4.0.13 for iOS lacks SSL Certificate Validation.

Q: How urgent is CVE-2021-27189?

Priority 42/100. Remotely exploitable, no login, no user action

This month

MEDIUM 5.9REMOTEUPGRADE

CVE-2021-27189 is a medium-severity flaw (CVSS 5.9) affecting canadian shield. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The CIRA Canadian Shield app before 4.0.13 for iOS lacks SSL Certificate Validation.

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	1.0% (top 36%)
CISA exploited list	No
Weakness	CWE-295
Published	2021-02-23
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: cira

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-02-23 00:15 UTCPublished CVE record published
2026-06-17 03:44 UTCUpdated Record last modified

cira canadian shield UPGRADE

Affected: < 4.0.13

Fixed in: 4.0.13

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy canadian-shield || rpm -q canadian-shield || canadian-shield --version

2. UPGRADE to 4.0.13 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade canadian-shield

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade canadian-shield

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-27189?

canadian shield: upgrade to 4.0.13. Exact commands for each OS are on this page.

Is CVE-2021-27189 being exploited?

CVE-2021-27189 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-27189 affect?

CVE-2021-27189 affects canadian shield. Severity is medium (CVSS 5.9). The CIRA Canadian Shield app before 4.0.13 for iOS lacks SSL Certificate Validation.

How urgent is CVE-2021-27189?

Priority 42/100. Remotely exploitable, no login, no user action

Software pages

iOS vulnerabilities

References

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