CVE-2019-0211
CVE-2019-0211 is a security flaw in Apache HTTP Server, one of the most widely used web servers. Attackers can run their own code on Apache HTTP Server. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 3 Nov 2021.[1]
Apache HTTP Server is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Apache has published a fix or advice.
Description
CISA calls it a privilege escalation in Apache HTTP Server. In its words: “Apache HTTP Server, with MPM event, worker or prefork, code executing in less-privileged child processes or threads (including scripts executed by an in-process scripting interpreter) could execute code with the privileges of the parent process (usually root) by manipulating the scoreboard.”[1]
The CVE record adds: “In Apache HTTP Server 2.4 releases 2.4.17 to 2.4.38, with MPM event, worker or prefork, code executing in less-privileged child processes or threads (including scripts executed by an in-process scripting interpreter) could execute arbitrary code with the privileges of the parent process (usually root) by manipulating the scoreboard. Non-Unix systems are not affected.”[2]
The underlying weakness is use after free (CWE-416), in MITRE’s list of common software weaknesses.
It scores 7.8 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; Apache’s advisory has them[3]. CISA names the product as Apache HTTP Server.
Most families won’t have Apache HTTP Server; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 3 Nov 2021, 940 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 3 May 2022 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 65%. That’s in the top 1% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
Apache has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]
- Check whether you use it.Apache HTTP Server is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed, or not in use. CISA gave US government agencies until 3 May 2022 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 7.8.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 65%.[4] |
See also
Other Apache HTTP Server flaws
- CVE-2024-38475: improper escaping of output ·
- CVE-2021-42013: path traversal ·
- CVE-2021-41773: path traversal ·
Other Apache flaws
- CVE-2016-3081, Apache Struts: command injection ·
- CVE-2026-34486, Apache Tomcat: missing encryption of sensitive data ·
- CVE-2026-34197, Apache ActiveMQ: improper input validation ·
- CVE-2025-24813, Apache Tomcat: path equivalence ·
- CVE-2024-45195, Apache OFBiz: forced browsing ·
Other use after free flaws
- CVE-2026-109619, PHP: stale internal request-state ·
- CVE-2026-109618, PHP: memory corruption ·
- CVE-2026-68820, Microsoft Windows Ancillary Function Driver for WinSock: use-after-free ·
- CVE-2010-0249, Microsoft Internet Explorer: use-after-free ·
- CVE-2020-9715, Adobe Acrobat: use-after-free ·
Added the same day
- CVE-2021-42258, BQE BillQuick Web Suite: SQL injection ·
- CVE-2021-42013, Apache HTTP Server: path traversal ·
- CVE-2021-41773, Apache HTTP Server: path traversal ·
- CVE-2021-40539, Zoho ManageEngine: aDSelfService plus authentication bypass ·
- CVE-2021-40444, Microsoft MSHTML: remote code execution ·
Every Apache flaw on CISA’s list · Everything added in November 2021
References
- ^ Cybersecurity and Infrastructure Security Agency. “Apache HTTP Server Privilege Escalation Vulnerability”. Known Exploited Vulnerabilities Catalog, added 3 Nov 2021.
- ^ National Institute of Standards and Technology. “CVE-2019-0211 Detail”. National Vulnerability Database, published 8 Apr 2019.
- ^ Apache. Advisories and fixes: httpd.apache.org, lists.apache.org, lists.fedoraproject.org, lists.fedoraproject.org, lists.fedoraproject.org, and 3 more on NVD’s record.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.650, percentile 99.2, 31 Oct 2026.
- CVE Program. “CVE-2019-0211”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.