CVE-2015-6835

highpriority · attend · 62EPSS 0.362 · 98 %ileexploit · functionalDEEURUUS

grimoire priorityP1 · Urgent

Exploitable?

Public exploit

2 exploits · functional

Likely / severe?

36.2% (98th) EPSS

CVSS 7.5 · high

Is it mine?

69 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · ads_tec_psirt

EPSS · scored 2026-10-27

The session deserializer in PHP before 5.4.45, 5.5.x before 5.5.29, and 5.6.x before 5.6.13 mishandles multiple php_var_unserialize calls, which allow remote attackers to execute arbitrary code or cause a denial of service (use-after-free) via crafted session content.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

Fixedads_tec_psirt
Update firmware to the latest version available. The issues have been resolved with IRF1000 version 1.5.0, IRF2000 version 4.4.0 and IRF3000 version 1.2.0.
Mitigationads_tec_psirt
It is recommended to disable all user accounts with restricted configuration write permissions if the update to the latest released version cannot be installed immediately.It is further recommended to use best practice password policies.

cvss

Technical severity, 0–10. One row per scoring source.

9.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 7.5–9.8

v2.07.5highAV:N/AC:L/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 10 · impact 6.4

v3.09.8criticalCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 5.9

v2.07.5highAV:N/AC:L/Au:N/C:P/I:P/A:Psecondary · FSTEC (BDU) RU

v3.09.8criticalCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Hsecondary · CVSS-BT (t0sche)

v3.09.8criticalCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · ads-tec PSIRT

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-416US

exploits (2)

Public proof-of-concept and weaponised exploit code.

EDB-38123PHP Session Deserializer - Use-After-Freefunctional · exploit_db
ockeghem/CVE-2015-6835-checkerockeghem/CVE-2015-6835-checkerPoC · poc_in_github

affected products (69)

Products and version ranges known to be affected.

Firmware 1.2.0 installed on IRF3000all versionsfixedads_tec_psirtDE
Firmware 1.5.0 installed on IRF1000all versionsfixedads_tec_psirtDE
Firmware 4.4.0 installed on IRF2000all versionsfixedads_tec_psirtDE
Firmware <1.2.0 installed on IRF3000all versionsads_tec_psirtDE
Firmware <1.5.0 installed on IRF1000all versionsads_tec_psirtDE
Firmware <4.4.0 installed on IRF2000all versionsads_tec_psirtDE
Debian Linuxall versionscert_bundDEcpe:/o:debian:debian_linux:-
Dell NetWorker <19.11.0.5all versionscert_bundDE
Dell NetWorker <19.13all versionscert_bundDE
F5 BIG-IPall versionscert_bundDEcpe:/a:f5:big-ip:-
F5 Enterprise Managerall versionscert_bundDEcpe:/a:f5:enterprise_manager:-
Open Source PHP <5.4.45all versionscert_bundDE
Open Source PHP <5.5.29all versionscert_bundDE
Open Source PHP <5.6.13all versionscert_bundDE
SUSE Linuxall versionscert_bundDEcpe:/o:suse:suse_linux:-
Ubuntu Linuxall versionscert_bundDEcpe:/o:canonical:ubuntu_linux:-
Xerox WorkCentreall versionscert_bundDEcpe:/h:xerox:workcentre:-
Dell Networker< 19.11.0.5cert_bundDE
Dell Networker< 19.13cert_bundDE
Open Source PHP< 5.4.45cert_bundDE

showing 20 of 69

advisories (2)

Vendor and ecosystem advisories describing this.

VDE-2023-009ads-tec: Multiple Vulnerabilities in IRF1000, IRF2000 and IRF30002023-05-08csaf · ads_tec_psirtDE
The affected products integrate the vulnerable libraries in a way so that the vulnerabilities can't be exploited remotely without prior authentication.
WID-SEC-W-2025-1425PHP: Mehrere SchwachstellenDeutsch2015-09-07csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in PHP ausnutzen, um beliebigen Code mit den Rechten des Dienstes auszuführen, um einen Denial of Service Zustand hervorrufen oder um Informationen offenzulegen.

also known as (5)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu ads_tec_psirt cert_bund NVD CVE.org MITRE

published 2016-05-16modified 2026-06-17

references (15)

External citations — patches, advisories, analysis.

scry

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