CVE-2017-5566: Code injection vulnerability in AVG Ultimate 17.1 (and earlier), AVG Internet Security 17.1 (and earlier), and

Routine

MEDIUM 6.7DOWNGRADEDOWNGRADEDOWNGRADE

CVE-2017-5566 is a medium-severity flaw (CVSS 6.7) affecting anti-virus, internet security, ultimate. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Code injection vulnerability in AVG Ultimate 17.1 (and earlier), AVG Internet Security 17.1 (and earlier), and AVG AntiVirus FREE 17.1 (and earlier) allows a local attacker to bypass a self-protection mechanism, inject arbitrary code, and take full control of any AVG process via a "DoubleAgent" attack. One perspective on this issue is that (1) these products do not use the Protected Processes feature, and therefore an attacker can enter an arbitr

Why this priority

No elevated risk signals yet

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	6.7 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	High
User interaction	None
EPSS exploit chance	0.6% (top 50%)
CISA exploited list	No
Weakness	CWE-427
Published	2017-03-21
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: avg

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2017-03-21 16:59 UTCPublished CVE record published
2026-06-17 01:20 UTCUpdated Record last modified

avg anti-virus DOWNGRADE

Affected: 17.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 17.1

1. Check installed version

apt-cache policy anti-virus || rpm -q anti-virus || anti-virus --version

2. No fixed release: DOWNGRADE to a release before 17.1 (Debian / Ubuntu)

apt-cache madison anti-virus sudo apt install anti-virus=<VERSION_BEFORE_17.1> sudo apt-mark hold anti-virus

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

dnf --showduplicates list anti-virus sudo dnf downgrade anti-virus-<VERSION_BEFORE_17.1> sudo dnf versionlock add anti-virus

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.

avg internet security DOWNGRADE

Affected: 17.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 17.1

1. Check installed version

apt-cache policy internet-security || rpm -q internet-security || internet-security --version

2. No fixed release: DOWNGRADE to a release before 17.1 (Debian / Ubuntu)

apt-cache madison internet-security sudo apt install internet-security=<VERSION_BEFORE_17.1> sudo apt-mark hold internet-security

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

dnf --showduplicates list internet-security sudo dnf downgrade internet-security-<VERSION_BEFORE_17.1> sudo dnf versionlock add internet-security

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.

avg ultimate DOWNGRADE

Affected: 17.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 17.1

1. Check installed version

apt-cache policy ultimate || rpm -q ultimate || ultimate --version

2. No fixed release: DOWNGRADE to a release before 17.1 (Debian / Ubuntu)

apt-cache madison ultimate sudo apt install ultimate=<VERSION_BEFORE_17.1> sudo apt-mark hold ultimate

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

dnf --showduplicates list ultimate sudo dnf downgrade ultimate-<VERSION_BEFORE_17.1> sudo dnf versionlock add ultimate

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.

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-2017-5566?

anti-virus: downgrade or apply the listed mitigation; internet security: downgrade or apply the listed mitigation; ultimate: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2017-5566 being exploited?

CVE-2017-5566 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-2017-5566 affect?

CVE-2017-5566 affects anti-virus, internet security, ultimate. Severity is medium (CVSS 6.7). Code injection vulnerability in AVG Ultimate 17.1 (and earlier), AVG Internet Security 17.1 (and earlier), and AVG AntiVirus FREE 17.1 (and earlier) allows a local attacker to bypass a self-protection mechanism, inject arbitrary code, and t

How urgent is CVE-2017-5566?

Priority 36/100. No elevated risk signals yet.

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References

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