CVE-2021-27135

Exploitation

Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.

SSVC decision

Not assessed by CISA

EPSS probability

7.54% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 94.0% of scored records. A rank, not a probability.

NVD base score

9.8 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

NVD analysis status

Modified. NVD last modified this record on 2026-06-17.

Red Hat severity

Important. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2021-02-10 15:51Z5 YR AGO

Last updated

2024-08-03 20:40Z2 YR AGO

Reserved

2021-02-10

Assigning CNA

mitre

Record state

PUBLISHED

Severity

Not rated by the issuing CNA

CNA CVSS vector

Not published by the issuing CNA

Weaknesses

• CWE-787Out-of-bounds WriteBase

Data version

5.1

Document digest

7222e248f9d80f474fd0292a87485e79af825619bf2787d9c81af47e233c6fd4

• www.openwall.comhttps://www.openwall.com/lists/oss-security/2021/02/09/7x_refsource_MISC
• www.openwall.comhttps://www.openwall.com/lists/oss-security/2021/02/09/9x_refsource_MISC
• www.openwall.com[oss-security] 20210210 Re: Re: screen crash processing combining charactershttp://www.openwall.com/lists/oss-security/2021/02/10/7mailing-listx_refsource_MLIST
• lists.debian.org[debian-lts-announce] 20210213 [SECURITY] [DLA 2558-1] xterm security updatehttps://lists.debian.org/debian-lts-announce/2021/02/msg00019.htmlmailing-listx_refsource_MLIST
• lists.fedoraproject.orgFEDORA-2021-e7a8e79fa8https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/35LK2ZXEIJUOGOA7FV2TJL3L6LFJ4X5S/vendor-advisoryx_refsource_FEDORA
• news.ycombinator.comhttps://news.ycombinator.com/item?id=26524650x_refsource_MISC
• access.redhat.comhttps://access.redhat.com/security/cve/CVE-2021-27135x_refsource_MISC
• bugzilla.redhat.comhttps://bugzilla.redhat.com/show_bug.cgi?id=1927559x_refsource_MISC
• invisible-island.nethttps://invisible-island.net/xterm/xterm.log.htmlx_refsource_CONFIRM
• github.comhttps://github.com/ThomasDickey/xterm-snapshots/commit/82ba55b8f994ab30ff561a347b82ea340ba7075cx_refsource_CONFIRM
• bugzilla.suse.comhttps://bugzilla.suse.com/show_bug.cgi?id=1182091x_refsource_CONFIRM
• seclists.org20210520 CVE-2021-31535 libX11 Insufficient Length Checks PoC and Archeologyhttp://seclists.org/fulldisclosure/2021/May/52mailing-listx_refsource_FULLDISC
• security.gentoo.orgGLSA-202208-22https://security.gentoo.org/glsa/202208-22vendor-advisoryx_refsource_GENTOO