CVE-2020-15158 | Heap buffer overflow in libIEC61850

In libIEC61850 before version 1.4.3, when a message with COTP message length field with value < 4 is received an integer underflow will happen leading to heap buffer overflow. This can cause an application crash or on some platforms even the execution of remote code. If your application is used in open networks or there are untrusted nodes in the network it is highly recommend to apply the patch. This was patched with commit 033ab5b. Users of version 1.4.x should upgrade to version 1.4.3 when available. As a workaround changes of commit 033ab5b can be applied to older versions.

Published: 2020-08-26 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-15158 is rated Moderate Risk (57.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.04%). 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-2020-15158

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 2.38% 2.04% -0.34%
2 2025-03-30 4.01% 2.38% -1.63%
3 2025-03-29 — 4.01% —

Full EPSS history (18 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-15158

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.7 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:H 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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.3 [email protected]
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 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:N)
No account or special rights needed—anonymous or random user is enough.
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:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P 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:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2020-15158

Affected software / configurations for CVE-2020-15158

Vendor Product Version Raw CPE
mz-automation libiec61850 >= 1.4.0, < 1.4.3 cpe:2.3:a:mz-automation:libiec61850:*:*:*:*:*:*:*:*

References for CVE-2020-15158

cvelogic Threat Intelligence