Description
Integer overflow in kbdint.c in mod_sftp in ProFTPD 1.3.4d and 1.3.5r3 allows remote attackers to cause a denial of service (memory consumption) via a large response count value in an authentication request, which triggers a large memory allocation.
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 | proftpd-dfsg | 1.3.5~rc3-2.1 | — |
| Debian 13 | proftpd-dfsg | 1.3.5~rc3-2.1 | — |
| Debian 12 | proftpd-dfsg | 1.3.5~rc3-2.1 | — |
| Debian 7 | proftpd-dfsg | 1.3.4a-5+deb7u1 | DSA-2767-1 |
| Debian 6.0 | proftpd-dfsg | 1.3.3a-6squeeze7 | DSA-2767-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | proftpd | 1.3.5b-2.5 | openSUSE-SU-2024:10048-1 |
Advisories 2
- DSA-2767-1 proftpd-dfsg - denial of service Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10048-1 proftpd-1.3.5b-2.5 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- http://kingcope.wordpress.com/2013/09/11/proftpd-mod_sftpmod_sftp_pam-invalid-pool-allocation-in-kbdint-authentication/
- [oss-security] 20130916 Re: CVE request: proftpd: mod_sftp/mod_sftp_pam invalid pool allocation during kbdint authentication mailing-list
- DSA-2767 vendor-advisory
- openSUSE-SU-2015:1031 vendor-advisory
- openSUSE-SU-2013:1563 vendor-advisory
- http://bugs.proftpd.org/show_bug.cgi?id=3973