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CVE-2021-33477

28
FAUCET Score

CVE-2021-33477 is a high-severity vulnerability affecting rxvt-unicode, rxvt, mrxvt, and Eterm, allowing for potential remote code execution due to improper handling of specific escape sequences. With a CVSS score of 8.8, it presents a significant risk, as an attacker with low privileges can exploit it over a network with low complexity, leading to high impact on confidentiality, integrity, and availability. Despite its severity, there is no evidence of active exploitation, no known public exploit code (Metasploit, Nuclei, ExploitDB), and minimal community discussion or media coverage beyond a single article.

Impacted Technologies

VendorProductVersion(s)CPE
0.9.7CPE matchmatch criteria
cpe:2.3:a:eterm_project:eterm:0.9.7:*:*:*:*:*:*:*
0.5.4CPE matchmatch criteria
cpe:2.3:a:mrxvt_project:mrxvt:0.5.4:*:*:*:*:*:*:*
9.22CPE matchmatch criteria
cpe:2.3:a:rxvt-unicode_project:rxvt-unicode:9.22:*:*:*:*:*:*:*
2.7.10CPE matchmatch criteria
cpe:2.3:a:rxvt_project:rxvt:2.7.10:*:*:*:*:*:*:*
33CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

8.8HIGH

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

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
2.8
Impact Score
5.9
CvssVersion
3.1

Exploit Intelligence

EPSS Score
4.09%
Probability of exploitation in next 30 days
EPSS Percentile
89.7%
Percentile rank of EPSS score among Peer Group
As of 2026-07-25
Model: v2026.06.15
This CVE's current EPSS score of 0.0409 is in the 89th percentile among its peer group of 17,822 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.3 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Remediation records are not available for this CVE.

References

cvs.schmorp.de / rxvt-unicode/Changes
Third Party Advisory
cvs.schmorp.de / rxvt-unicode/src/command.C
PatchThird Party Advisory
git.enlightenment.org / apps/eterm.git/log
Third Party Advisory
lists.debian.org / debian-lts-announce/2021/05/msg00026.html
Mailing ListThird Party Advisory
lists.debian.org / debian-lts-announce/2021/06/msg00010.html
Mailing ListThird Party Advisory
lists.debian.org / debian-lts-announce/2021/06/msg00011.html
Mailing ListThird Party Advisory
lists.debian.org / debian-lts-announce/2021/06/msg00012.html
Mailing ListThird Party Advisory
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/6RFMU5YXXNYYVA7G2DAHRXXHO6JKVFUT
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/AO52OLNOOKOCZSJCN3R7Q25XA32BWNWP
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/DUV4LDVZVW7KCGPAMFZD4ZJ4FVLPOX4C
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/NZWGE2RJONBEHSPCBUAW72NTRTIFKZAX
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/SLPVEPBH37EBR4R54RMC6GD33J37HJXD
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/UXAKO6N6NKTR6Z6KVAPEXSZQMRU52SGA
packetstormsecurity.com / files/162621/rxvt-2.7.0-rxvt-unicode-9.22-Code-Execution.html
ExploitThird Party AdvisoryVDB Entry
security.gentoo.org / glsa/202105-17
Third Party Advisory
security.gentoo.org / glsa/202209-07
Third Party Advisory
sourceforge.net / projects/materm/files/mrxvt%20source
ProductThird Party Advisory
sourceforge.net / projects/rxvt/files/rxvt-dev
ProductThird Party Advisory
openwall.com / lists/oss-security/2017/05/01/20
Mailing ListThird Party Advisory
openwall.com / lists/oss-security/2021/05/17/1
ExploitMailing ListThird Party Advisory