CVE-2015-8597: Open redirect vulnerability in Blue Coat ProxySG 6.5 before 6.5.8.8 and 6.6 and Advanced Secure Gateway (ASG)

This month

HIGH 7.4UPGRADEDOWNGRADE

CVE-2015-8597 is a high-severity flaw (CVSS 7.4) affecting proxysg, advanced secure gateway. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Open redirect vulnerability in Blue Coat ProxySG 6.5 before 6.5.8.8 and 6.6 and Advanced Secure Gateway (ASG) 6.6 might allow remote attackers to redirect users to arbitrary web sites and conduct phishing attacks via a base64-encoded URL in conjunction with a "clear text" one in a coaching page, as demonstrated by "http://www.%humbug-URL%.local/bluecoat-splash-API?%BASE64-URL%."

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	7.4 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.9% (top 20%)
CISA exploited list	No
Published	2016-01-08
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: bluecoat

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

Am I affected?

Timeline

2016-01-08 19:59 UTCPublished CVE record published
2026-06-17 00:34 UTCUpdated Record last modified

bluecoat proxysg UPGRADE

Affected: <= 6.5.8.7

Fixed in: newer than 6.5.8.7

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 6.5.8.7 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade proxysg

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade proxysg

Note

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

bluecoat advanced secure gateway DOWNGRADE

Affected: 6.6

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.6

1. Check installed version

apt-cache policy advanced-secure-gateway || rpm -q advanced-secure-gateway || advanced-secure-gateway --version

2. No fixed release: DOWNGRADE to a release before 6.6 (Debian / Ubuntu)

apt-cache madison advanced-secure-gateway sudo apt install advanced-secure-gateway=<VERSION_BEFORE_6.6> sudo apt-mark hold advanced-secure-gateway

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

dnf --showduplicates list advanced-secure-gateway sudo dnf downgrade advanced-secure-gateway-<VERSION_BEFORE_6.6> sudo dnf versionlock add advanced-secure-gateway

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-2015-8597?

proxysg: upgrade to newer than 6.5.8.7; advanced secure gateway: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2015-8597 being exploited?

CVE-2015-8597 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-2015-8597 affect?

CVE-2015-8597 affects proxysg, advanced secure gateway. Severity is high (CVSS 7.4). Open redirect vulnerability in Blue Coat ProxySG 6.5 before 6.5.8.8 and 6.6 and Advanced Secure Gateway (ASG) 6.6 might allow remote attackers to redirect users to arbitrary web sites and conduct phishing attacks via a base64-encoded URL in

How urgent is CVE-2015-8597?

Priority 51/100. High severity; Public exploit reference

Related CVEs

CVE-2021-46825 CRITICAL 9.1 DOWNGRADE DOWNGRADE Symantec Advanced Secure Gateway (ASG) and ProxySG are susceptible to an HTTP desync vulnerability
CVE-2016-6594 HIGH 7.5 DOWNGRADE DOWNGRADE Blue Coat Advanced Secure Gateway 6.6, CacheFlow 3.4, ProxySG 6.5 and 6.6 allows remote attackers to bypass bl
CVE-2013-5959 HIGH 7.1 DOWNGRADE UPGRADE Blue Coat ProxySG before 6.2.14.1, 6.3.x, 6.4.x, and 6.5 before 6.5.2 allows remote attackers to cause a denia
CVE-2011-5124 HIGH 10.0 MITIGATE DOWNGRADE Stack-based buffer overflow in the BCAAA component before build 60258, as used by Blue Coat ProxySG 4.2.3 thro
CVE-2010-5192 MEDIUM 4.3 UPGRADE MITIGATE Cross-site scripting (XSS) vulnerability in the Java Management Console in Blue Coat ProxySG before SGOS 4.3.4

References

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