CVE-2009-1647: Heap-based buffer overflow in popcorn.exe in Ultrafunk Popcorn 1.87 allows remote POP3 servers to cause a deni

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HIGH 9.3DOWNGRADE

CVE-2009-1647 is a high-severity flaw (CVSS 9.3) affecting popcorn. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Heap-based buffer overflow in popcorn.exe in Ultrafunk Popcorn 1.87 allows remote POP3 servers to cause a denial of service (application crash) via a long string in a +OK response. NOTE: some of these details are obtained from third party information.

Why this priority

Critical severity
Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	9.3 (High)
EPSS exploit chance	2.7% (top 14%)
CISA exploited list	No
Weakness	CWE-119
Published	2009-05-15
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: ultrafunk

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2009-05-15 15:30 UTCPublished CVE record published
2026-06-16 23:07 UTCUpdated Record last modified

ultrafunk popcorn DOWNGRADE

Affected: 1.87

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.87

1. Check installed version

apt-cache policy popcorn || rpm -q popcorn || popcorn --version

2. No fixed release: DOWNGRADE to a release before 1.87 (Debian / Ubuntu)

apt-cache madison popcorn sudo apt install popcorn=<VERSION_BEFORE_1.87> sudo apt-mark hold popcorn

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list popcorn sudo dnf downgrade popcorn-<VERSION_BEFORE_1.87> sudo dnf versionlock add popcorn

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: Popcorn 1.87 - Remote Heap Overflow (PoC)

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2009-1647?

popcorn: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2009-1647 being exploited?

CVE-2009-1647 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2009-1647 affect?

CVE-2009-1647 affects popcorn. Severity is high (CVSS 9.3). Heap-based buffer overflow in popcorn.exe in Ultrafunk Popcorn 1.87 allows remote POP3 servers to cause a denial of service (application crash) via a long string in a +OK response. NOTE: some of these details are obtained from third party

How urgent is CVE-2009-1647?

Priority 59/100. Critical severity; Public exploit reference

References

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