CVE-2017-9841
This CVE is being exploited. Apply the vendor fix, or take the service off the internet until you can, then check your logs for attempts.
What it is
Util/PHP/eval-stdin.php in PHPUnit before 4.8.28 and 5.x before 5.6.3 allows remote attackers to execute arbitrary PHP code via HTTP POST data beginning with a "<?php " substring, as demonstrated by an attack on a site with an exposed /vendor folder, i.e., external access to the /vendor/phpunit/phpunit/src/Util/PHP/eval-stdin.php URI.
Live exploitation on the huntback network (30 days)
Detection
Evidence
Confirmed exploited. Our decoys saw 3,493 exploitation attempts in the last 14 days; CISA added it to KEV 1731 days ago.
Last attempt. 18,969 attempts on our decoys, 3,493 in the last 14 days
First exploitation attempt on our decoys
Added to CISA Known Exploited Vulnerabilities
Published
Exploit code published (ExploitDB)
Nuclei detection template available
Observed: our own decoys saw it. Reported: CISA, the vendor or another named source says so. Weaponised: public exploit code or a scanner template exists. Methodology
Questions
Is CVE-2017-9841 being exploited in the wild?
Yes. The huntback decoy network captured 18,969 exploitation attempts from 466 distinct source IPs; the most recent was on 2026-11-12. It is also in the CISA KEV catalogue.
Can CVE-2017-9841 be detected on the network?
Yes. huntback carries a network signature for CVE-2017-9841, so attempts against a decoy are tagged in real time.
How huntback helps
Deploy a decoy that emulates Communications Diameter Signaling Router and you will see every attempt at this CVE the moment it lands, with the full payload, the attacker's infrastructure, and any stage-2 loader. Then huntback can scan the attacker back.
Related
NVD record → Browse all CVEs → Live malware and C2 finds → Novel-attack discovery → Deploy a decoy →API
This record, with its evidence timeline, as JSON:
curl -H "X-API-Key: $HUNTBACK_KEY" https://app.huntback.io/api/v1/evidence/CVE-2017-9841