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CVE-2011-1575· NVD / CVE Program· CNA redhat

The STARTTLS implementation in ftp_parser.c in Pure-FTPd before 1.0.30 does not properly restrict I/O buffering, which allows man-in-the-mid

The STARTTLS implementation in ftp_parser.c in Pure-FTPd before 1.0.30 does not properly restrict I/O buffering, which allows man-in-the-middle attackers to insert commands into encrypted FTP sessions by sending a cleartext command that is processed after TLS is in place, related to a "plaintext command injection" attack, a similar issue to CVE-2011-0411.

MediumCVSS 5.8 · v2.0—Proof of concept Fix available
Published
May 23, 2011
Updated
Jun 16, 2026
EPSS
33.3% · 98th percentile
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Action score

33

Monitor

Low priority for now.

CVSS
23 / 40 · 5.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
10 / 30 · 33.3%

Affected systems

VendorProduct
pureftpdpure-ftpd

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • pureftpd pure-ftpdup to 1.0.29 inclusive
  • pureftpd pure-ftpd0.90
  • pureftpd pure-ftpd0.91
  • pureftpd pure-ftpd0.92
  • pureftpd pure-ftpd0.93
  • pureftpd pure-ftpd0.94
  • pureftpd pure-ftpd0.95
  • pureftpd pure-ftpd0.95-pre1
  • pureftpd pure-ftpd0.95-pre2
  • pureftpd pure-ftpd0.95-pre3
  • pureftpd pure-ftpd0.95-pre4
  • pureftpd pure-ftpd0.95.1
  • pureftpd pure-ftpd0.95.2
  • pureftpd pure-ftpd0.96
  • pureftpd pure-ftpd0.96.1
  • pureftpd pure-ftpd0.96pre1
  • pureftpd pure-ftpd0.97-final
  • pureftpd pure-ftpd0.97.1
  • pureftpd pure-ftpd0.97.2
  • pureftpd pure-ftpd0.97.3

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12pure-ftpdbefore 1.0.30-11.0.30-1

Same product

pureftpd: all records

Other highest-scoring records for the same primary product.

  • CVE-2017-12170Downstream version 1.0.46-1 of pure-ftpd as shipped in Fedora was vulnerable to packaging error due to which the original configuration was
    39Monitor
  • CVE-2024-48208pure-ftpd before 1.0.52 is vulnerable to Buffer Overflow.
    34Monitor
  • CVE-2020-9274An issue was discovered in Pure-FTPd 1.0.49.
    32Monitor
  • CVE-2020-9365An issue was discovered in Pure-FTPd 1.0.49.
    32Monitor
  • CVE-2021-40524In Pure-FTPd before 1.0.50, an incorrect max_filesize quota mechanism in the server allows attackers to upload files of unbounded size, whic
    31Monitor
  • CVE-2020-35359Pure-FTPd 1.0.48 allows remote attackers to prevent legitimate server use by making enough connections to exceed the connection limit.
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:pure-ftpd1.0.30-1 · Debian:12Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:02017-10-17

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. First PoC+2338 d
  3. TodaySep 30, 2026+5608 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

    If successful

    Confidentiality
    P · data can be read
    Integrity
    P · data or configuration can be modified
    Availability
    none
    Attack complexity
    M
    Confidentiality impact
    P
    Integrity impact
    P
    Availability impact
    None

    Weakness class (CWE)

    CWE-399 · Resource Management Errors

    CVSS vector

    AV:N/AC:M/Au:N/C:P/I:P/A:N

    nvd-primary

    Attack context

    MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

    MITRE has no CAPEC/ATT&CK mapping for this CWE.

    Noroxi analysis

    No Noroxi analysis for this record yet

    We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.

    We use this product, ask for help

    Change log

    1. Fix✗ → ✓

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    References

    Vendor advisories and official records. Exploit/PoC links are deliberately left out.

    All records