CVE-2011-0340: Multiple buffer overflows in the ISSymbol ActiveX control in ISSymbol.ocx 61.6.0.0 and 301.1009.2904.0 in the

Q: How do I fix CVE-2011-0340?

advantech studio: downgrade or apply the listed mitigation; thin client: downgrade or apply the listed mitigation; web studio: upgrade to newer than 7.0. Exact commands for each OS are on this page.

Q: Is CVE-2011-0340 being exploited?

CVE-2011-0340 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2011-0340 affect?

CVE-2011-0340 affects advantech studio, thin client, web studio. Severity is high (CVSS 9.3). Multiple buffer overflows in the ISSymbol ActiveX control in ISSymbol.ocx 61.6.0.0 and 301.1009.2904.0 in the ISSymbol virtual machine, as distributed in Advantech Studio 6.1 SP6 61.6.01.05, InduSoft Web Studio before 7.0+SP1, and InduSoft

Q: How urgent is CVE-2011-0340?

Priority 62/100. Critical severity; EPSS top 2%: very likely to be exploited; Public exploit reference

This week

HIGH 9.3DOWNGRADEDOWNGRADEUPGRADE

CVE-2011-0340 is a high-severity flaw (CVSS 9.3) affecting advantech studio, thin client, web studio. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Multiple buffer overflows in the ISSymbol ActiveX control in ISSymbol.ocx 61.6.0.0 and 301.1009.2904.0 in the ISSymbol virtual machine, as distributed in Advantech Studio 6.1 SP6 61.6.01.05, InduSoft Web Studio before 7.0+SP1, and InduSoft Thin Client 7.0, allow remote attackers to execute arbitrary code via a long (1) InternationalOrder, (2) InternationalSeparator, or (3) LogFileName property value; or (4) a long bstrFileName argument to the Ope

Why this priority

Critical severity
EPSS top 2%: very likely to be exploited
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	9.3 (High)
EPSS exploit chance	32.3% (top 2%)
CISA exploited list	No
Weakness	CWE-119
Published	2011-05-04
Last modified	2026-06-16

Publisher (CNA): Flexera Software LLC · Vendor: advantech · indusoft

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2011-05-04 22:55 UTCPublished CVE record published
2026-06-16 23:27 UTCUpdated Record last modified

advantech advantech studio DOWNGRADE

Affected: 6.1 sp6_61.6.01.05

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.1

1. Check installed version

apt-cache policy advantech-studio || rpm -q advantech-studio || advantech-studio --version

2. No fixed release: DOWNGRADE to a release before 6.1 (Debian / Ubuntu)

apt-cache madison advantech-studio sudo apt install advantech-studio=<VERSION_BEFORE_6.1> sudo apt-mark hold advantech-studio

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list advantech-studio sudo dnf downgrade advantech-studio-<VERSION_BEFORE_6.1> sudo dnf versionlock add advantech-studio

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

indusoft thin client DOWNGRADE

Affected: 7.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.0

1. Check installed version

apt-cache policy thin-client || rpm -q thin-client || thin-client --version

2. No fixed release: DOWNGRADE to a release before 7.0 (Debian / Ubuntu)

apt-cache madison thin-client sudo apt install thin-client=<VERSION_BEFORE_7.0> sudo apt-mark hold thin-client

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list thin-client sudo dnf downgrade thin-client-<VERSION_BEFORE_7.0> sudo dnf versionlock add thin-client

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

indusoft web studio UPGRADE

Affected: <= 7.0 · 6.1 · 6.1 sp6

Fixed in: newer than 7.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy web-studio || rpm -q web-studio || web-studio --version

2. UPGRADE to newer than 7.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade web-studio

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade web-studio

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: InduSoft Web Studio - 'ISSymbol.ocx InternationalSeparator()' Heap Overflow (Metasploit)
Metasploit: InduSoft Web Studio ISSymbol.ocx InternationalSeparator() Heap Overflow

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2011-0340?

advantech studio: downgrade or apply the listed mitigation; thin client: downgrade or apply the listed mitigation; web studio: upgrade to newer than 7.0. Exact commands for each OS are on this page.

Is CVE-2011-0340 being exploited?

CVE-2011-0340 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2011-0340 affect?

CVE-2011-0340 affects advantech studio, thin client, web studio. Severity is high (CVSS 9.3). Multiple buffer overflows in the ISSymbol ActiveX control in ISSymbol.ocx 61.6.0.0 and 301.1009.2904.0 in the ISSymbol virtual machine, as distributed in Advantech Studio 6.1 SP6 61.6.01.05, InduSoft Web Studio before 7.0+SP1, and InduSoft

How urgent is CVE-2011-0340?

Priority 62/100. Critical severity; EPSS top 2%: very likely to be exploited; Public exploit reference

Software pages

Advantech vulnerabilities

Related CVEs

CVE-2013-1627 HIGH 7.8 DOWNGRADE DOWNGRADE Absolute path traversal vulnerability in NTWebServer.exe in Indusoft Studio 7.0 and earlier and Advantech Stud
CVE-2011-0488 HIGH 10.0 DOWNGRADE DOWNGRADE Stack-based buffer overflow in NTWebServer.exe in the test web service in InduSoft NTWebServer, as distributed

References

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