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Bug 74704 - net-ftp/tnftp-20030825: does not check for directory escapes
Summary: net-ftp/tnftp-20030825: does not check for directory escapes
Alias: None
Product: Gentoo Security
Classification: Unclassified
Component: Vulnerabilities (show other bugs)
Hardware: All All
: High normal (vote)
Assignee: Gentoo Security
Whiteboard: B2 [glsa]
Depends on:
Reported: 2004-12-16 15:46 UTC by Sascha Silbe
Modified: 2005-01-13 17:50 UTC (History)
1 user (show)

See Also:
Package list:
Runtime testing required: ---


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Description Sascha Silbe 2004-12-16 15:46:39 UTC
Advisory from

Date: 15 Dec 2004 08:28:52 -0000
From: "D. J. Bernstein" <>
Subject: [remote] [control] tnftp 20030825 does not check for directory escapes
Mailing-List: contact; run by ezmlm
Automatic-Legal-Notices: See

Yosef Klein, a student in my Fall 2004 UNIX Security Holes course, has
discovered a remotely exploitable security hole in tnftp, an FTP client,
version 20030825 (current at least in FreeBSD ports). I'm publishing
this notice, but all the discovery credits should be assigned to Klein.

You are at risk if you use tnftp to download a batch of files from an
FTP server. Anyone who provides an FTP response to tnftp (not
necessarily the legitimate server administrator; an attacker can modify
FTP responses passing through the network) then has complete control
over your account: he can read and modify your files, watch the programs
you're running, etc.

The bug is triggered by the server sending a file name with slashes,
such as /home/you/.cshrc. The mget() function in cmds.c blindly uses the
server's file name (cp) as a local file name (tp passed to recvrequest);
users normally expect file-transfer programs to check for escapes from
the current directory.

---D. J. Bernstein, Associate Professor, Department of Mathematics,
Statistics, and Computer Science, University of Illinois at Chicago
Comment 1 Matthias Geerdsen (RETIRED) gentoo-dev 2004-12-18 13:45:00 UTC
Grant, you commited the ebuild... maybe you can verify/advise
Comment 2 Thierry Carrez (RETIRED) gentoo-dev 2004-12-21 07:02:40 UTC
Candidate: CAN-2004-1294
Reference: MISC:

The mget function in cmds.c for tnftp 20030825 allows remote FTP
servers to overwrite arbitrary files via FTP responses containing file
names with / (slash) characters.
Comment 3 Thierry Carrez (RETIRED) gentoo-dev 2004-12-30 07:11:18 UTC
This is
But they don't seem to find much more than we do.
Comment 4 Grant Goodyear (RETIRED) gentoo-dev 2005-01-08 12:17:51 UTC
Version bumped to fix the security hole.  Need testing by sparc, ppc, alpha,
and amd64, please.
Comment 5 Jason Wever (RETIRED) gentoo-dev 2005-01-09 06:45:51 UTC
Stable on sparc.
Comment 6 Thierry Carrez (RETIRED) gentoo-dev 2005-01-09 09:49:13 UTC
Was never stable on ppc and amd64, removing them from Cc...
Comment 7 Bryan Østergaard (RETIRED) gentoo-dev 2005-01-11 10:30:00 UTC
Stable on alpha.
Comment 8 Luke Macken (RETIRED) gentoo-dev 2005-01-13 17:50:57 UTC
GLSA 200501-24