Bug 2502961

Summary: CVE-2026-63091 proftpd: signed integer overflow via SCP size-record parser [epel-all]
Product: [Fedora] Fedora EPEL Reporter: Guilherme de Almeida Suckevicz <gsuckevi>
Component: proftpdAssignee: Paul Howarth <paul>
Status: CLOSED ERRATA QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: high Docs Contact:
Priority: high    
Version: epel10CC: paul
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["a8222ef6-073f-4f6d-b413-1eb7668d2a08"]}
Fixed In Version: proftpd-1.3.8d-4.el9 proftpd-1.3.6e-11.el8 Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2026-08-06 00:32:51 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Guilherme de Almeida Suckevicz 2026-07-20 19:21:22 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

ProFTPD before 1.3.9c and 1.3.10rc3 contains a signed integer overflow vulnerability in the mod_sftp module's SCP size-record parser that allows authenticated low-privilege attackers to bypass ASLR by sending a crafted file size value of UINT64_MAX, which results in a negative off_t value. Attackers can exploit the subsequent conversion to uint32_t, causing an approximately 4 GB requested read length and forcing the server to read beyond the end of the SSH channel data and write overread process memory into the uploaded file. In tested configurations, the disclosed data contains libc, libcrypto, and PIE pointers sufficient to derive their randomized base addresses, thereby bypassing ASLR and enabling reliable exploitation of memory corruption vulnerabilities in the same process.

Comment 1 Fedora Update System 2026-07-28 18:35:13 UTC
FEDORA-EPEL-2026-cbb4ce3efc (proftpd-1.3.6e-11.el8) has been submitted as an update to Fedora EPEL 8.
https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2026-cbb4ce3efc

Comment 2 Fedora Update System 2026-07-28 18:35:22 UTC
FEDORA-EPEL-2026-daf1e2cc13 (proftpd-1.3.8d-4.el9) has been submitted as an update to Fedora EPEL 9.
https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2026-daf1e2cc13

Comment 3 Fedora Update System 2026-07-29 01:04:25 UTC
FEDORA-EPEL-2026-daf1e2cc13 has been pushed to the Fedora EPEL 9 testing repository.

You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2026-daf1e2cc13

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 4 Fedora Update System 2026-07-29 01:19:34 UTC
FEDORA-EPEL-2026-cbb4ce3efc has been pushed to the Fedora EPEL 8 testing repository.

You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2026-cbb4ce3efc

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 5 Fedora Update System 2026-08-06 00:32:51 UTC
FEDORA-EPEL-2026-daf1e2cc13 (proftpd-1.3.8d-4.el9) has been pushed to the Fedora EPEL 9 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 6 Fedora Update System 2026-08-06 00:44:35 UTC
FEDORA-EPEL-2026-cbb4ce3efc (proftpd-1.3.6e-11.el8) has been pushed to the Fedora EPEL 8 stable repository.
If problem still persists, please make note of it in this bug report.