CVE-2015-7540

The LDAP server in the AD domain controller in Samba 4.x before 4.1.22 does not check return values to ensure successful ASN.1 memory allocation, which allows remote attackers to cause a denial of service (memory consumption and daemon crash) via crafted packets.

Published: 2015-12-29 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2015-7540 is rated Moderate Risk (60.4/100): CVSS High severity, with high exploitation likelihood (EPSS 39.60%, 97th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize 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-2015-7540

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 2026-05-13 43.30% 39.60% -3.70%
2 2025-12-28 39.60% 43.30% +3.70%
3 2025-12-27 — 39.60% —

Full EPSS history (21 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2015-7540

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/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:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2015-7540

OS Trackers for CVE-2015-7540

vendor priority summary link
debian not yet assigned CVE-2015-7540 not yet assigned priority: Debian including 1 source packages (samba), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2015-7540
gentoo normal CVE-2015-7540: 1 GLSA(s) (201612-47), 1 atom(s) (net-fs/samba); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2015-7540
redhat medium — https://access.redhat.com/security/cve/CVE-2015-7540
ubuntu medium CVE-2015-7540 medium priority: Ubuntu including 2 source packages (samba, samba4), 16 status rows across 8 suites (precise, trusty, upstream, vivid, wily, xenial, yakkety, zesty): released 8, DNE 6, ignored 1, not-affected 1. https://ubuntu.com/security/CVE-2015-7540

Affected software / configurations for CVE-2015-7540

Vendor Product Version Raw CPE
samba samba >= 4.0.0, < 4.1.22 cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:*
canonical ubuntu_linux 12.04 cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:-:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 15.04 cpe:2.3:o:canonical:ubuntu_linux:15.04:*:*:*:*:*:*:*
canonical ubuntu_linux 15.10 cpe:2.3:o:canonical:ubuntu_linux:15.10:*:*:*:*:*:*:*
debian debian_linux 7.0 cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*

References for CVE-2015-7540

URL Tags
http://lists.fedoraproject.org/pipermail/package-announce/2015-December/174076.html Third Party Advisory
http://lists.fedoraproject.org/pipermail/package-announce/2015-December/174391.html Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00033.html Mailing List Third Party Advisory
http://www.debian.org/security/2016/dsa-3433 Third Party Advisory
http://www.oracle.com/technetwork/topics/security/linuxbulletinjan2016-2867209.html Third Party Advisory
http://www.securityfocus.com/bid/79736 Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1034492 Third Party Advisory VDB Entry
http://www.ubuntu.com/usn/USN-2855-1 Third Party Advisory
http://www.ubuntu.com/usn/USN-2855-2 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1288451 Issue Tracking Third Party Advisory
https://git.samba.org/?p=samba.git%3Ba=commit%3Bh=530d50a1abdcdf4d1775652d4c456c1274d83d8d
https://git.samba.org/?p=samba.git%3Ba=commit%3Bh=9d989c9dd7a5b92d0c5d65287935471b83b6e884
https://security.gentoo.org/glsa/201612-47 Third Party Advisory
https://www.samba.org/samba/security/CVE-2015-7540.html Vendor Advisory
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