Description
encoding.c in GNU Screen through 4.8.0 allows remote attackers to cause a denial of service (invalid write access and application crash) or possibly have unspecified other impact via a crafted UTF-8 character sequence.
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 | screen | 4.8.0-5 | — |
| Debian 13 | screen | 4.8.0-5 | — |
| Debian 12 | screen | 4.8.0-5 | — |
| Debian 10 | screen | 4.6.2-3+deb10u1 | DSA-4861-1 |
| Debian 9 | screen | 4.5.0-6+deb9u1 | DLA-2570-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | screen | 4.8.0-1ubuntu0.1 | USN-4747-1 |
| Ubuntu 18.04 LTS | screen | 4.6.2-1ubuntu1.1 | USN-4747-1 |
| Ubuntu 16.04 LTS | screen | 4.3.1-2ubuntu0.1 | USN-4747-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 14.04 LTS | screen | 4.1.0~20120320gitdb59704-9ubuntu0.1~esm2 | USN-4747-2 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | screen | 4.1.0-0.27.20120314git3c2946.el7_9 | RHSA-2021:0742 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7.7 TUS | screen | 4.1.0-0.25.20120314git3c2946.el7_7.1 | RHSA-2022:1074 |
| RHEL 7.7 E4S | screen | 4.1.0-0.25.20120314git3c2946.el7_7.1 | RHSA-2022:1074 |
| RHEL 7.7 AUS | screen | 4.1.0-0.25.20120314git3c2946.el7_7.1 | RHSA-2022:1074 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | screen | 4.6.2-5.3.1 | SUSE-SU-2021:0492-1 |
| SLES 15 SP1 | screen | 4.6.2-5.3.1 | SUSE-SU-2021:0492-1 |
| SLES 15 | screen | 4.6.2-5.3.1 | SUSE-SU-2021:0492-1 |
| SLES 12 SP5 | screen | 4.0.4-23.6.1 | SUSE-SU-2021:0491-1 |
| SLES 12 SP4 | screen | 4.0.4-23.6.1 | SUSE-SU-2021:0491-1 |
Show 20 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | screen | 4.0.4-23.6.1 | SUSE-SU-2021:0491-1 |
| SLES 12 SP2 | screen | 4.0.4-23.6.1 | SUSE-SU-2021:0491-1 |
| SLES for SAP 15 SP1 | screen | 4.6.2-5.3.1 | SUSE-SU-2021:0492-1 |
| SLES for SAP 15 | screen | 4.6.2-5.3.1 | SUSE-SU-2021:0492-1 |
| SLES for SAP 12 SP5 | screen | 4.0.4-23.6.1 | SUSE-SU-2021:0491-1 |
| SLES for SAP 12 SP4 | screen | 4.0.4-23.6.1 | SUSE-SU-2021:0491-1 |
| SLES for SAP 12 SP3 | screen | 4.0.4-23.6.1 | SUSE-SU-2021:0491-1 |
| SLES for SAP 12 SP2 | screen | 4.0.4-23.6.1 | SUSE-SU-2021:0491-1 |
| SLE HPC 15 SP1 | screen | 4.6.2-5.3.1 | SUSE-SU-2021:0492-1 |
| SLE HPC 15 | screen | 4.6.2-5.3.1 | SUSE-SU-2021:0492-1 |
| SUSE OpenStack Cloud Crowbar 9 | screen | 4.0.4-23.6.1 | SUSE-SU-2021:0491-1 |
| SUSE OpenStack Cloud Crowbar 8 | screen | 4.0.4-23.6.1 | SUSE-SU-2021:0491-1 |
| SUSE OpenStack Cloud 9 | screen | 4.0.4-23.6.1 | SUSE-SU-2021:0491-1 |
| SUSE OpenStack Cloud 8 | screen | 4.0.4-23.6.1 | SUSE-SU-2021:0491-1 |
| SUSE OpenStack Cloud 7 | screen | 4.0.4-23.6.1 | SUSE-SU-2021:0491-1 |
| SUSE Manager Server 4.0 | screen | 4.6.2-5.3.1 | SUSE-SU-2021:0492-1 |
| SUSE Manager Retail Branch Server 4.0 | screen | 4.6.2-5.3.1 | SUSE-SU-2021:0492-1 |
| SUSE Manager Proxy 4.0 | screen | 4.6.2-5.3.1 | SUSE-SU-2021:0492-1 |
| SUSE HPE Helion OpenStack 8 | screen | 4.0.4-23.6.1 | SUSE-SU-2021:0491-1 |
| SUSE Enterprise Storage 6 | screen | 4.6.2-5.3.1 | SUSE-SU-2021:0492-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | screen | 4.9.0-1.1 | openSUSE-SU-2024:11884-1 |
| openSUSE Leap 15.2 | screen | 4.6.2-lp152.6.3.1 | openSUSE-SU-2021:0304-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | screen | 4.8.0-r4 | — |
| Alpine v3.23 | screen | 4.8.0-r4 | — |
| Alpine v3.22 | screen | 4.8.0-r4 | — |
| Alpine v3.21 | screen | 4.8.0-r4 | — |
| Alpine v3.20 | screen | 4.8.0-r4 | — |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | screen | 4.8.0-r4 | — |
| Alpine v3.18 | screen | 4.8.0-r4 | — |
| Alpine v3.17 | screen | 4.8.0-r4 | — |
| Alpine v3.16 | screen | 4.8.0-r4 | — |
| Alpine v3.15 | screen | 4.8.0-r4 | — |
| Alpine v3.14 | screen | 4.8.0-r4 | — |
| Alpine v3.13 | screen | 4.8.0-r4 | — |
| Alpine v3.12 | screen | 4.8.0-r1 | — |
| Alpine v3.11 | screen | 4.7.0-r2 | — |
| Alpine v3.10 | screen | 4.6.2-r2 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | screen | 4.1.0-0.27.20120314git3c2946.amzn2 | ALAS2-2021-1623 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 2 (CBL-Mariner) | screen | 4.9.1-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | screen | 4.1.0-0.27.20120314git3c2946.el7_9 | ELSA-2021-0742 |
Advisories 12
- RHSA-2021:0742 Red Hat Security Advisory: screen security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-4861-1 screen - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2570-1 screen - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-4747-1 screen vulnerability Ubuntu Security Notices (USN) · Feb 10, 2026
- USN-4747-2 screen vulnerability Ubuntu Security Notices (USN) · Feb 10, 2026
- SUSE-SU-2021:0491-1 Security update for screen SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:0304-1 Security update for screen SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:11884-1 screen-4.9.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2022:1074 Red Hat Security Advisory: screen security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- SUSE-SU-2021:0492-1 Security update for screen SUSE / openSUSE Security Updates · May 2, 2025
- ALAS2-2021-1623 Important: screen security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Mar 25, 2021
- ELSA-2021-0742 Important: screen security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Mar 9, 2021
References
- https://lists.gnu.org/archive/html/screen-devel/2021-02/msg00000.html
- https://www.openwall.com/lists/oss-security/2021/02/09/3
- https://ftp.gnu.org/gnu/screen/
- [oss-security] 20210210 Re: screen crash processing combining characters mailing-list
- [debian-lts-announce] 20210219 [SECURITY] [DLA 2570-1] screen security update mailing-list
- DSA-4861 vendor-advisory
- FEDORA-2021-5e9894a0c5 vendor-advisory
- FEDORA-2021-9107eeb95c vendor-advisory
- GLSA-202105-11 vendor-advisory