CVE-2021-3139

In Open-iSCSI tcmu-runner 1.3.x, 1.4.x, and 1.5.x through 1.5.2, xcopy_locate_udev in tcmur_cmd_handler.c lacks a check for transport-layer restrictions, allowing remote attackers to read or write files via directory traversal in an XCOPY request. For example, an attack can occur over a network if the attacker has access to one iSCSI LUN. NOTE: relative to CVE-2020-28374, this is a similar mistake in a different algorithm.

Published: 2021-01-13 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-3139 is rated Moderate Risk (63.4/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.65%). EPSS rose +1.71% over the last day, indicating growing attacker interest. Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-3139

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.94% 2.65% +1.71%
2 2025-11-21 0.76% 0.94% +0.17%
3 2025-11-18 — 0.76% —

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-3139

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.1 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 5.2 [email protected]
5.5 2.0 MEDIUM
AV:N/AC:L/Au:S/C:P/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 8.0 4.9 [email protected]

Weakness enumeration for CVE-2021-3139

OS Trackers for CVE-2021-3139

vendor priority summary link
debian not yet assigned CVE-2021-3139 not yet assigned priority: Debian including 1 source packages (tcmu), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-3139
redhat high — https://access.redhat.com/security/cve/CVE-2021-3139
ubuntu medium CVE-2021-3139 medium priority: Ubuntu including 1 source packages (tcmu), 16 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 7, DNE 3, needed 3, released 2, needs-triage 1. https://ubuntu.com/security/CVE-2021-3139

Affected software / configurations for CVE-2021-3139

Vendor Product Version Raw CPE
tcmu-runner_project tcmu-runner >= 1.3.0, <= 1.5.2 cpe:2.3:a:tcmu-runner_project:tcmu-runner:*:*:*:*:*:*:*:*

References for CVE-2021-3139

URL Tags
http://www.openwall.com/lists/oss-security/2021/01/13/5 Mailing List Mitigation Third Party Advisory
https://bugzilla.suse.com/attachment.cgi?id=844938 Issue Tracking Third Party Advisory
https://bugzilla.suse.com/show_bug.cgi?id=1178372 Issue Tracking Third Party Advisory
https://github.com/open-iscsi/tcmu-runner/pull/644 Patch Third Party Advisory
https://www.openwall.com/lists/oss-security/2021/01/12/12 Mailing List Third Party Advisory
cvelogic Threat Intelligence