---
title: "Security digest: July 13, 2021"
url: https://erroneo.us/security/2021-07-13/
description: "July 13, 2021 vulnerability digest: 1 brief (ProxyOracle). What to patch and who can relax."
type: security-digest-day
section: "Security Digest"
date_published: 2021-07-13
date_modified: 2026-10-23
publisher: erroneo.us
author: erroneo.us Security Desk
license: All rights reserved. Quote with attribution and a link.
---

# Security digest: July 13, 2021

1 editorial brief.

## Take stock

- Check exposure: ProxyOracle . Anyone with an on-premises Exchange 2013, 2016 or 2019 server still on a build older than the July 2021 Security Update, especially with Outlook Web Access reachable from the internet.
- None of it touches your stack? Then there is nothing to do today. That is a result, not a failure to read carefully.

## Editorial briefs

- **Check exposure** [Exchange CVE-2021-31196: ProxyOracle Padding Oracle in KEV](https://erroneo.us/security/briefs/exchange-cve-2021-31196-proxyoracle-padding-oracle/index.md): Fixed in July 2021 and flagged as exploited only in 2024; the real question is whether any Exchange server that old still runs, because one that does has far bigger problems than this bug.

## Known exploited (CISA KEV)

None.

## Critical advisories

None.

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Source page: https://erroneo.us/security/2021-07-13/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt