CVE-2020-8243

From Exploited flaws, HARD’s guide to the flaws being used in attacks · Checked
This article is about a flaw in Ivanti Pulse Connect Secure. For every flaw being used in attacks, see Exploited flaws; for Ivanti’s, see Ivanti flaws being used in attacks.

CVE-2020-8243 is a security flaw in Ivanti Pulse Connect Secure, a VPN companies use to let staff in from outside. Someone who already has a way in can use Ivanti Pulse Connect Secure to run their own code. 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]

Ivanti Pulse Connect Secure 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. Ivanti has published a fix or advice.

Description

CISA calls it a code execution in Ivanti Pulse Connect Secure. In its words: “Ivanti Pulse Connect Secure contains an unspecified vulnerability in the admin web interface that could allow an authenticated attacker to upload a custom template to perform code execution.”[1]

The underlying weakness is code injection (CWE-94), in MITRE’s list of common software weaknesses.[2]

It scores 7.2 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; Ivanti’s advisory has them[3]. CISA names the product as Ivanti Pulse Connect Secure.

Most families won’t have Ivanti Pulse Connect Secure; it’s for whoever looks after IT at work.

Exploitation

CISA added it to its catalog of known exploited vulnerabilities on 3 Nov 2021, 399 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 91%. 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

Ivanti has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]

  1. Check whether you use it.Ivanti Pulse Connect Secure 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.
  2. 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.
  3. 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

DateEvent
The flaw is made public in the National Vulnerability Database, with a severity score of 7.2.[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 91%.[4]

See also

Other Ivanti Pulse Connect Secure flaws

Other Ivanti flaws

  • CVE-2026-118527, Ivanti Connect Secure: generation of predictable numbers or identifiers ·
  • CVE-2026-111357, Ivanti Connect Secure: missing authentication for critical function ·
  • CVE-2026-104935, Ivanti Connect Secure: authentication bypass by spoofing ·
  • CVE-2026-10520, Ivanti Sentry: OS command injection ·
  • CVE-2026-6973, Ivanti Endpoint Manager Mobile (EPMM): improper input validation ·

Other code injection flaws

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 Ivanti flaw on CISA’s list · Everything added in November 2021

References

  1. ^ Cybersecurity and Infrastructure Security Agency. “Ivanti Pulse Connect Secure Code Execution Vulnerability”. Known Exploited Vulnerabilities Catalog, added 3 Nov 2021.
  2. ^ National Institute of Standards and Technology. “CVE-2020-8243 Detail”. National Vulnerability Database, published 30 Sep 2020.
  3. ^ Ivanti. Advisories and fixes: kb.pulsesecure.net.
  4. ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.908, percentile 99.8, 31 Oct 2026.
  5. CVE Program. “CVE-2020-8243”. 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.