Description
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.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | curl | 7.55.0-1 | — |
| Debian 13 | curl | 7.55.0-1 | — |
| Debian 12 | curl | 7.55.0-1 | — |
| Debian 9 | curl | 7.52.1-5+deb9u1 | DSA-3992-1 |
| Debian 8 | curl | 7.38.0-4+deb8u6 | DSA-3992-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 7 | curl | 7.26.0-1+wheezy20 | DLA-1062-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | curl | 7.47.0-1ubuntu2.3 | USN-3441-1 |
| Ubuntu 14.04 LTS | curl | 7.35.0-1ubuntu2.11 | USN-3441-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 3 | httpd24-curl +2 | 7.61.1-1.el6 | RHSA-2018:3558 |
| RHEL 3 | httpd24-httpd +5 | 2.4.34-7.el6 | RHSA-2018:3558 |
| RHEL 3 | httpd24-mod_md | 2.4.34-7.el7 | RHSA-2018:3558 |
| RHEL 3 | httpd24-mod_ssl +1 | 1:2.4.34-7.el6 | RHSA-2018:3558 |
| RHEL 3 | httpd24-nghttp2 +2 | 1.7.1-7.el6 | RHSA-2018:3558 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | curl | 7.37.0-37.3.1 | SUSE-SU-2017:2174-1 |
| SLES 12 SP2 | curl | 7.37.0-37.3.1 | SUSE-SU-2017:2174-1 |
| SLES 11 SP4 | curl | 7.19.7-1.70.3.1 | SUSE-SU-2017:2312-1 |
| SLES 11 | curl-openssl1 | 7.19.7-1.70.3.1 | SUSE-SU-2017:2312-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Studio Onsite 1.3 | curl | 7.19.7-1.20.53.3.1 | SUSE-SU-2017:2354-1 |
| SLES for SAP 12 SP3 | curl | 7.37.0-37.3.1 | SUSE-SU-2017:2174-1 |
| SLES for SAP 12 SP2 | curl | 7.37.0-37.3.1 | SUSE-SU-2017:2174-1 |
| SLES for SAP 11 SP4 | curl | 7.19.7-1.70.3.1 | SUSE-SU-2017:2312-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | curl | 7.79.1-1.1 | openSUSE-SU-2024:10582-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | curl | 7.55.0-r0 | — |
| Alpine v3.23 | curl | 7.55.0-r0 | — |
| Alpine v3.22 | curl | 7.55.0-r0 | — |
| Alpine v3.21 | curl | 7.55.0-r0 | — |
| Alpine v3.20 | curl | 7.55.0-r0 | — |
Show 17 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | curl | 7.55.0-r0 | — |
| Alpine v3.18 | curl | 7.55.0-r0 | — |
| Alpine v3.17 | curl | 7.55.0-r0 | — |
| Alpine v3.16 | curl | 7.55.0-r0 | — |
| Alpine v3.15 | curl | 7.55.0-r0 | — |
| Alpine v3.14 | curl | 7.55.0-r0 | — |
| Alpine v3.13 | curl | 7.55.0-r0 | — |
| Alpine v3.12 | curl | 7.55.0-r0 | — |
| Alpine v3.11 | curl | 7.55.0-r0 | — |
| Alpine v3.10 | curl | 7.55.0-r0 | — |
| Alpine v3.9 | curl | 7.55.0-r0 | — |
| Alpine v3.8 | curl | 7.55.0-r0 | — |
| Alpine v3.7 | curl | 7.55.0-r0 | — |
| Alpine v3.6 | curl | 7.55.0-r0 | — |
| Alpine v3.5 | curl | 7.55.0-r0 | — |
| Alpine v3.4 | curl | 7.55.0-r0 | — |
| Alpine v3.3 | curl | 7.55.0-r0 | — |
Advisories 13
- RHSA-2018:3558 Red Hat Security Advisory: httpd24 security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- USN-3441-1 curl vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DSA-3992-1 curl - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1062-1 curl - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10582-1 curl-7.79.1-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:2174-1 Security update for curl SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:2354-1 Security update for curl SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:2312-1 Security update for curl SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2026-0180 Dell Data Protection Advisor: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jan 20, 2026
- VDE-2019-009 PHOENIX CONTACT: Multiple Vulnerabilities in AXC F 2152 CERT@VDE · May 22, 2025
- WID-SEC-2025-0370 Apple Mac OS: Mehrere Schwachstellen BSI CERT-Bund (WID) · Feb 13, 2025
- WID-SEC-2023-1647 cURL: Mehrere Schwachstellen ermöglichen Offenlegung von Informationen BSI CERT-Bund (WID) · Jul 4, 2023
- ICSA-19-155-01 PHOENIX CONTACT PLCNext AXC F 2152 CISA ICS & IT advisories · Jun 4, 2019
References
- https://support.apple.com/HT208221
- 100286 vdb-entry
- RHSA-2018:3558 vendor-advisory
- GLSA-201709-14 vendor-advisory
- 1039118 vdb-entry
- https://curl.haxx.se/docs/adv_20170809B.html
- DSA-3992 vendor-advisory