| 1 |
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - |
| 2 |
Gentoo Linux Security Advisory GLSA 202105-11 |
| 3 |
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - |
| 4 |
https://security.gentoo.org/ |
| 5 |
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - |
| 6 |
|
| 7 |
Severity: Normal |
| 8 |
Title: GNU Screen: User-assisted execution of arbitrary code |
| 9 |
Date: May 26, 2021 |
| 10 |
Bugs: #769770 |
| 11 |
ID: 202105-11 |
| 12 |
|
| 13 |
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - |
| 14 |
|
| 15 |
Synopsis |
| 16 |
======== |
| 17 |
|
| 18 |
A vulnerability in GNU screen may allow a remote attacker to execute |
| 19 |
arbitrary code. |
| 20 |
|
| 21 |
Background |
| 22 |
========== |
| 23 |
|
| 24 |
GNU Screen is a full-screen window manager that multiplexes a physical |
| 25 |
terminal between several processes, typically interactive shells. |
| 26 |
|
| 27 |
Affected packages |
| 28 |
================= |
| 29 |
|
| 30 |
------------------------------------------------------------------- |
| 31 |
Package / Vulnerable / Unaffected |
| 32 |
------------------------------------------------------------------- |
| 33 |
1 app-misc/screen < 4.8.0-r2 >= 4.8.0-r2 |
| 34 |
|
| 35 |
Description |
| 36 |
=========== |
| 37 |
|
| 38 |
It was discovered that GNU screen did not properly handle certain UTF-8 |
| 39 |
character sequences. |
| 40 |
|
| 41 |
Impact |
| 42 |
====== |
| 43 |
|
| 44 |
A remote attacker could entice a user to run a program where attacker |
| 45 |
controls the output inside a GNU screen session, possibly resulting in |
| 46 |
execution of arbitrary code with the privileges of the process or a |
| 47 |
Denial of Service condition. |
| 48 |
|
| 49 |
Workaround |
| 50 |
========== |
| 51 |
|
| 52 |
This vulnerability can be mitigated by disabling UTF-8 processing in |
| 53 |
.screenrc. |
| 54 |
|
| 55 |
Resolution |
| 56 |
========== |
| 57 |
|
| 58 |
All GNU screen users should upgrade to the latest version: |
| 59 |
|
| 60 |
# emerge --sync |
| 61 |
# emerge --ask --oneshot --verbose ">=app-misc/screen-4.8.0-r2" |
| 62 |
|
| 63 |
References |
| 64 |
========== |
| 65 |
|
| 66 |
[ 1 ] CVE-2021-26937 |
| 67 |
https://nvd.nist.gov/vuln/detail/CVE-2021-26937 |
| 68 |
|
| 69 |
Availability |
| 70 |
============ |
| 71 |
|
| 72 |
This GLSA and any updates to it are available for viewing at |
| 73 |
the Gentoo Security Website: |
| 74 |
|
| 75 |
https://security.gentoo.org/glsa/202105-11 |
| 76 |
|
| 77 |
Concerns? |
| 78 |
========= |
| 79 |
|
| 80 |
Security is a primary focus of Gentoo Linux and ensuring the |
| 81 |
confidentiality and security of our users' machines is of utmost |
| 82 |
importance to us. Any security concerns should be addressed to |
| 83 |
security@g.o or alternatively, you may file a bug at |
| 84 |
https://bugs.gentoo.org. |
| 85 |
|
| 86 |
License |
| 87 |
======= |
| 88 |
|
| 89 |
Copyright 2021 Gentoo Foundation, Inc; referenced text |
| 90 |
belongs to its owner(s). |
| 91 |
|
| 92 |
The contents of this document are licensed under the |
| 93 |
Creative Commons - Attribution / Share Alike license. |
| 94 |
|
| 95 |
https://creativecommons.org/licenses/by-sa/2.5 |
Archives