Your message dated Tue, 18 Aug 2026 21:48:31 +0000
with message-id <[email protected]>
and subject line Bug#1142904: fixed in unzip 6.0-29+deb13u1
has caused the Debian Bug report #1142904,
regarding unzip: heap OOB read in EF_IZUNIX3 extra field handler
[CAN-2026-2034440]
to be marked as done.
This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.
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--
1142904: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1142904
Debian Bug Tracking System
Contact [email protected] with problems
--- Begin Message ---
Package: unzip
Version: 6.0-28
Severity: grave
Tags: security
X-Debbugs-Cc: [email protected], [email protected]
Hi,
InfoZIP unzip 6.0 contains a heap out-of-bounds read in the
ef_scan_for_izux() function in process.c when processing EF_IZUNIX3
(ID 0x7875) extra field blocks. This is a missed variant of
CVE-2014-8139 — that fix addressed the EF_IZUNIX (0x5855) and
EF_IZUNIX2 (0x7855) handlers but did NOT patch the EF_IZUNIX3 (0x7875)
handler.
CAN: CAN-2026-2034440 (pending assignment from MITRE)
CWE: CWE-125 (Out-of-bounds Read)
CVSS: 6.1 Medium
ROOT CAUSE (process.c, line 2988):
uid_size = *((EB_HEADSIZE + 1) + ef_buf);
gid_size = *((EB_HEADSIZE + uid_size + 2) + ef_buf); // OOB READ
The only validation is `eb_len >= EB_UX3_MINLEN` (i.e., eb_len >= 7).
uid_size is attacker-controlled (a byte value 0-255, read from ef_buf
at a fixed offset). With uid_size=200 and eb_len=7, the gid_size read
at offset (EB_HEADSIZE + 200 + 2) = 206 reads 199 bytes past the end
of the 7-byte extra field data. The subsequent read_ux3_value() calls
at offsets (EB_HEADSIZE + 2) and (EB_HEADSIZE + uid_size + 3) compound
the over-read.
TRIGGER: unzip -o poc.zip (extraction mode) where poc.zip contains a
file entry with an EF_IZUNIX3 extra field block with eb_len=7 and
uid_size=200.
ASAN OUTPUT (Debian unzip 6.0, built with -fsanitize=address
-DIZ_HAVE_UXUIDGID):
==12==ERROR: AddressSanitizer: heap-buffer-overflow on address
0xffffafe007de at pc 0xaaaae3888d50
READ of size 1 at 0xffffafe007de thread T0
#0 ef_scan_for_izux /build/unzip-6.0/process.c:2988:28
#1 get_extattribs /build/unzip-6.0/unix/unix.c:1063:36
#2 close_outfile /build/unzip-6.0/unix/unix.c:1115:23
#3 extract_or_test_member /build/unzip-6.0/extract.c:2122:9
#4 extract_or_test_entrylist /build/unzip-6.0/extract.c:1748:22
#5 extract_or_test_files /build/unzip-6.0/extract.c:741:17
IMPACT: Heap OOB read causing crash (DoS). The OOB-read value is used
as a UID for chown() on the extracted file, so an attacker can also
influence file ownership. Active on all distributions that compile with
-DIZ_HAVE_UXUIDGID (Debian, Ubuntu, Red Hat, SUSE).
SUGGESTED FIX (add bounds checks matching the CVE-2014-8139 pattern):
uid_size = *((EB_HEADSIZE + 1) + ef_buf);
+ if (uid_size + 3 > eb_len)
+ break;
gid_size = *((EB_HEADSIZE + uid_size + 2) + ef_buf);
+ if (uid_size + gid_size + 3 > eb_len)
+ break;
Best regards,
Akhil Koul
--- End Message ---
--- Begin Message ---
Source: unzip
Source-Version: 6.0-29+deb13u1
Done: Santiago Vila <[email protected]>
We believe that the bug you reported is fixed in the latest version of
unzip, which is due to be installed in the Debian FTP archive.
A summary of the changes between this version and the previous one is
attached.
Thank you for reporting the bug, which will now be closed. If you
have further comments please address them to [email protected],
and the maintainer will reopen the bug report if appropriate.
Debian distribution maintenance software
pp.
Santiago Vila <[email protected]> (supplier of updated unzip package)
(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing [email protected])
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512
Format: 1.8
Date: Tue, 11 Aug 2026 00:10:00 +0200
Source: unzip
Architecture: source
Version: 6.0-29+deb13u1
Distribution: trixie-security
Urgency: high
Maintainer: Santiago Vila <[email protected]>
Changed-By: Santiago Vila <[email protected]>
Closes: 1142904 1142905 1142906
Changes:
unzip (6.0-29+deb13u1) trixie-security; urgency=high
.
* Apply upstream fix for CAN-2026-2034440. Closes: #1142904.
(heap out-of-bounds read in EF_IZUNIX3 extra field handler)
* Apply upstream fix for CAN-2026-2034443. Closes: #1142905.
(stack out-of-bounds NUL write in EF_SMARTZIP handler)
* Apply upstream fix for CAN-2026-2034442. Closes: #1142906.
(heap buffer overflow WRITE in memextract() STORED path)
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unzip_6.0-29+deb13u1.debian.tar.xz
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Files:
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62b490407489521db863b523a7f86375 1376845 utils optional unzip_6.0.orig.tar.gz
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