CVE-2020-14933: compose.php in SquirrelMail 1.4.22 calls unserialize for the $attachments value, which originates from an HTTP

This month

HIGH 8.8DOWNGRADE

CVE-2020-14933 is a high-severity flaw (CVSS 8.8) affecting squirrelmail. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

compose.php in SquirrelMail 1.4.22 calls unserialize for the $attachments value, which originates from an HTTP POST request. NOTE: the vendor disputes this because these two conditions for PHP object injection are not satisfied: existence of a PHP magic method (such as __wakeup or __destruct), and any attack-relevant classes must be declared before unserialize is called (or must be autoloaded).

Why this priority

High severity

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	1.4% (top 27%)
CISA exploited list	No
Weakness	CWE-502
Published	2020-06-20
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: squirrelmail

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

Am I affected?

Timeline

2020-06-20 13:15 UTCPublished CVE record published
2026-06-17 02:55 UTCUpdated Record last modified

squirrelmail squirrelmail DOWNGRADE

Affected: 1.4.22

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.4.22

1. Check installed version

apt-cache policy squirrelmail || rpm -q squirrelmail || squirrelmail --version

2. No fixed release: DOWNGRADE to a release before 1.4.22 (Debian / Ubuntu)

apt-cache madison squirrelmail sudo apt install squirrelmail=<VERSION_BEFORE_1.4.22> sudo apt-mark hold squirrelmail

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list squirrelmail sudo dnf downgrade squirrelmail-<VERSION_BEFORE_1.4.22> sudo dnf versionlock add squirrelmail

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2020-14933?

squirrelmail: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-14933 being exploited?

CVE-2020-14933 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-2020-14933 affect?

CVE-2020-14933 affects squirrelmail. Severity is high (CVSS 8.8). compose.php in SquirrelMail 1.4.22 calls unserialize for the $attachments value, which originates from an HTTP POST request. NOTE: the vendor disputes this because these two conditions for PHP object injection are not satisfied: existence o

How urgent is CVE-2020-14933?

Priority 49/100. High severity

Software pages

PHP vulnerabilities

Related CVEs

CVE-2020-14932 CRITICAL 9.8 DOWNGRADE compose.php in SquirrelMail 1.4.22 calls unserialize for the $mailtodata value, which originates from an HTTP

References

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