CVE-2017-1000100

What it is

When doing a TFTP transfer and curl/libcurl is given a URL that contains a very long file name (longer than about 515 bytes), the file name is truncated to fit within the buffer boundaries, but the buffer size is still wrongly updated to use the untruncated length. This too large value is then used in the sendto() call, making curl attempt to send more data than what is actually put into the buffer. The endto() function will then read beyond the end of the heap based buffer. A malicious HTTP(S) server could redirect a vulnerable libcurl-using client to a crafted TFTP URL (if the client hasn't restricted which protocols it allows redirects to) and trick it to send private memory contents to a remote server over UDP. Limit curl's redirect protocols with --proto-redir and libcurl's with CURLOPT_REDIR_PROTOCOLS.

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure.

Exploit odds

4.0% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2017-10-05 01:29 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 00:58 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 4.0% in the next 30 days (EPSS).
• Severity: 6.5 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2017-10-05 01:29 UTC

Last modified

2026-06-17 00:58 UTC

Exploit probability

4.0% · EPSS, next 30 days

Weakness

CWE-200 · Information exposure

Record status

Modified

Affected

• Haxx Libcurl 7.15.0
• Haxx Libcurl 7.15.1
• Haxx Libcurl 7.15.2
• Haxx Libcurl 7.15.3
• Haxx Libcurl 7.15.4
• Haxx Libcurl 7.15.5
• Haxx Libcurl 7.16.0
• Haxx Libcurl 7.16.1

Attack profile CVSS 3.1 · 6.5

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2017-1000100.md and follow it. Check whether this project is affected by CVE-2017-1000100. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

Copy as ticket · More options · Status badge