Important EPSS 0.01581 2019-07 archive

Executive Summary

A cross-site-scripting (XSS) vulnerability exists when Microsoft Exchange Server does not properly sanitize a specially crafted web request to an affected Exchange server. An authenticated attacker could exploit the vulnerability by sending a specially crafted request to an affected server. The attacker who successfully exploited the vulnerability could then perform cross-site scripting attacks on affected systems and run script in the security context of the current user. The attacks could allow the attacker to read content that the attacker is not authorized to read, use the victim's identity to take actions on the Exchange server on behalf of the user, such as change permissions and delete content, and inject malicious content in the browser of the user. The security update addresses the vulnerability by helping to ensure that Exchange Server properly sanitizes web requests.

Overview

Important
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
Category Spoofing
Released Jul 9 2019
Last Updated Jul 9 2019
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.01581 — 0.72336 percentile

EPSS Score

0.01581
probability of exploitation in the next 30 days
0.72336 percentile - updated 2026-06-20
View on FIRST.org

Affected Products

5 affected products
Product KB Article Severity Impact Restart Required
Microsoft Exchange Server 2013 Cumulative Update 23 4509409 (Security Update) 4509409 (Security Update) 4509409 (Security Update) Important Spoofing Maybe
Microsoft Exchange Server 2016 Cumulative Update 12 4509409 (Security Update) 4509409 (Security Update) 4509409 (Security Update) Important Spoofing Maybe
Microsoft Exchange Server 2016 Cumulative Update 13 4509409 (Security Update) 4509409 (Security Update) 4509409 (Security Update) Important Spoofing Maybe
Microsoft Exchange Server 2019 Cumulative Update 1 4509408 (Security Update) 4509408 (Security Update) Important Spoofing Maybe
Microsoft Exchange Server 2019 Cumulative Update 2 4509408 (Security Update) 4509408 (Security Update) Important Spoofing Maybe

Patches

2 patches
Article Type Restart
4509409 (Security Update) 4509409 (Security Update) 4509409 Security Update Maybe
4509408 (Security Update) 4509408 Security Update Maybe

Known Exploits

Acknowledgments