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CVE-2004-2771

28
FAUCET Score

CVE-2004-2771 describes a command injection vulnerability in the expand function of fio.c within Heirloom mailx (12.5 and earlier) and BSD mailx (8.1.2 and earlier), allowing remote attackers to execute arbitrary commands through shell metacharacters in email addresses. With a CVSS score of 7.5, this vulnerability is easily exploitable over the network without authentication, potentially leading to partial compromise of confidentiality, integrity, and availability. Despite its age and high media coverage for its time, there is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or inclusion in CISA's KEV catalog, indicating low current exploitation risk.

Impacted Technologies

VendorProductVersion(s)CPE
6CPE matchmatch criteria
cpe:2.3:o:oracle:linux:6:*:*:*:*:*:*:*
7CPE matchmatch criteria
cpe:2.3:o:oracle:linux:7:*:*:*:*:*:*:*
6.0CPE matchmatch criteria
cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*
7.0CPE matchmatch criteria
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
<= 8.1.2CPE matchmatch criteria
cpe:2.3:a:bsd_mailx_project:bsd_mailx:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 2.0

7.5HIGH

AV:N/AC:L/Au:N/C:P/I:P/A:P

Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Exploitability Score
10.0
Impact Score
6.4
CvssVersion
2.0

Exploit Intelligence

EPSS Score
6.86%
Probability of exploitation in next 30 days
EPSS Percentile
93.3%
Percentile rank of EPSS score among Peer Group
As of 2026-07-25
Model: v2026.06.15
This CVE's current EPSS score of 0.0686 is in the 89th percentile among its peer group of 51,485 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 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

Patch Available

Vendor Patches (11)

microsoftpatch availablevia msrc
Product: cbl2 mailx 12.5-34 on CBL Mariner 2.0Fixed in: 12.5-34
microsoftpatch availablevia msrc
Product: azl3 mailx 12.5-36 on Azure Linux 3.0Fixed in: 12.5-36
microsoftpatch availablevia msrc
Product: 19521-16823Fixed in: 12.5-34
microsoftpatch availablevia msrc
Product: 19522-17084Fixed in: 12.5-36
microsoftpatch availablevia msrc
Product: CBL Mariner 2.0 ARMFixed in: 12.5-34
microsoftpatch availablevia msrc
Product: Azure Linux 3.0 x64Fixed in: 12.5-36
microsoftpatch availablevia msrc
Product: Azure Linux 3.0 ARMFixed in: 12.5-36
microsoftpatch availablevia msrc
Product: CBL Mariner 2.0 x64Fixed in: 12.5-34
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 6Fixed in: mailx-0:12.4-8.el6_6
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: mailx-0:12.5-12.el7_0
View patch
redhatend of lifevia redhat_api
Product: Red Hat Enterprise Linux 5Fixed in: mailx

Vendor Advisories (4)

microsoft2024-Jun/CVE-2004-2771

CVE-2004-2771

Jun 11, 2024
microsoft2021-Dec/CVE-2004-2771

CVE-2004-2771

Dec 14, 2021
redhatCVE-2004-2771Moderate

mailx: command execution flaw

Dec 16, 2014
microsoft2014-Dec/CVE-2004-2771Important

The expand function in fio.c in Heirloom mailx 12.5 and earlier and BSD mailx 8.1.2 and earlier allows remote attackers to execute arbitrary commands via shell metacharacters in an email address.

Dec 2, 2014

References

linux.oracle.com / errata/ELSA-2014-1999.html
rhn.redhat.com / errata/RHSA-2014-1999.html
bugs.debian.org / cgi-bin/bugreport.cgi
Exploit
seclists.org / oss-sec/2014/q4/1066
secunia.com / advisories/60940
secunia.com / advisories/61585
secunia.com / advisories/61693
debian.org / security/2014/dsa-3105