CVE-2010-4221

CVE-2010-4221 is a critical-severity vulnerability in Proftpd with a CVSS 2.0 base score of 10.0. Its EPSS exploit-prediction score of 91% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-119.

Key facts

Description

Multiple stack-based buffer overflows in the pr_netio_telnet_gets function in netio.c in ProFTPD before 1.3.3c allow remote attackers to execute arbitrary code via vectors involving a TELNET IAC escape character to a (1) FTP or (2) FTPS server.

Frequently asked questions

What is CVE-2010-4221?
Multiple stack-based buffer overflows in the pr_netio_telnet_gets function in netio.c in ProFTPD before 1.3.3c allow remote attackers to execute arbitrary code via vectors involving a TELNET IAC escape character to a (1) FTP or (2) FTPS server.
How severe is CVE-2010-4221?
CVE-2010-4221 has a CVSS 2.0 base score of 10.0, rated critical severity.
Is CVE-2010-4221 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 91% (100th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2010-4221?
CVE-2010-4221 primarily affects Proftpd. In total, 15 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2010-4221?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2010-4221 published?
CVE-2010-4221 was published on 2010-11-09 and last updated on 2026-06-16.

References

Affected products (15)

More vulnerabilities in Proftpd

All CVEs affecting Proftpd →

Other CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities

Browse all CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities →