CVE-2013-0731: ajax.functions.php in the MailUp plugin before 1.3.3 for WordPress does not properly restrict access to unspec

Q: How do I fix CVE-2013-0731?

wp-mailup: upgrade to newer than 1.3.2. Exact commands for each OS are on this page.

Q: Is CVE-2013-0731 being exploited?

CVE-2013-0731 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-2013-0731 affect?

CVE-2013-0731 affects wp-mailup. Severity is medium (CVSS 5.0). ajax.functions.php in the MailUp plugin before 1.3.3 for WordPress does not properly restrict access to unspecified Ajax functions, which allows remote attackers to modify plugin settings and conduct cross-site scripting (XSS) attacks by se

Q: How urgent is CVE-2013-0731?

Priority 44/100. Public exploit reference

This month

MEDIUM 5.0UPGRADE

CVE-2013-0731 is a medium-severity flaw (CVSS 5.0) affecting wp-mailup. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

ajax.functions.php in the MailUp plugin before 1.3.3 for WordPress does not properly restrict access to unspecified Ajax functions, which allows remote attackers to modify plugin settings and conduct cross-site scripting (XSS) attacks by setting the wordpress_logged_in cookie. NOTE: this is due to an incomplete fix for a similar issue that was fixed in 1.3.2.

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	2.6% (top 15%)
CISA exploited list	No
Weakness	CWE-264
Published	2013-03-22
Last modified	2026-06-16

Publisher (CNA): Flexera Software LLC · Vendor: mailup

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2013-03-22 15:55 UTCPublished CVE record published
2026-06-16 23:49 UTCUpdated Record last modified

mailup wp-mailup UPGRADE

Affected: <= 1.3.2 · 1.0.0 · 1.1.0 · 1.1.1 · 1.1.2 · 1.1.3 · 1.2 · 1.3

Fixed in: newer than 1.3.2

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy wp-mailup || rpm -q wp-mailup || wp-mailup --version

2. UPGRADE to newer than 1.3.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade wp-mailup

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade wp-mailup

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-2013-0731?

wp-mailup: upgrade to newer than 1.3.2. Exact commands for each OS are on this page.

Is CVE-2013-0731 being exploited?

CVE-2013-0731 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-2013-0731 affect?

CVE-2013-0731 affects wp-mailup. Severity is medium (CVSS 5.0). ajax.functions.php in the MailUp plugin before 1.3.3 for WordPress does not properly restrict access to unspecified Ajax functions, which allows remote attackers to modify plugin settings and conduct cross-site scripting (XSS) attacks by se

How urgent is CVE-2013-0731?

Priority 44/100. Public exploit reference

Software pages

WordPress vulnerabilities · PHP vulnerabilities

Related CVEs

CVE-2013-2640 MEDIUM 5.0 UPGRADE ajax.functions.php in the MailUp plugin before 1.3.2 for WordPress does not properly restrict access to unspec

References

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