How severe is CVE-1999-1273?

CVE-1999-1273 has a CVSS 2.0 base score of 7.5, rated high severity.

Is CVE-1999-1273 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-1999-1273?

CVE-1999-1273 affects National Science Foundation Squid Web Proxy. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-1999-1273?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-1999-1273 published?

CVE-1999-1273 was published on 1998-02-20 and last updated on 2026-06-16.

CVE-1999-1273

CVE-1999-1273 is a high-severity vulnerability in National Science Foundation Squid Web Proxy with a CVSS 2.0 base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 2.0 base score 7.5)
EPSS exploit prediction: 1% (67th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: National Science Foundation Squid Web Proxy
Published: 1998-02-20
Last modified: 2026-06-16

Description

Squid Internet Object Cache 1.1.20 allows users to bypass access control lists (ACLs) by encoding the URL with hexadecimal escape sequences.

Frequently asked questions

What is CVE-1999-1273?: Squid Internet Object Cache 1.1.20 allows users to bypass access control lists (ACLs) by encoding the URL with hexadecimal escape sequences.
How severe is CVE-1999-1273?: CVE-1999-1273 has a CVSS 2.0 base score of 7.5, rated high severity.
Is CVE-1999-1273 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-1999-1273?: CVE-1999-1273 affects National Science Foundation Squid Web Proxy. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-1999-1273?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-1999-1273 published?: CVE-1999-1273 was published on 1998-02-20 and last updated on 2026-06-16.

References

Affected products (1)

cpe:2.3:a:national_science_foundation:squid_web_proxy:1.1.20:*:*:*:*:*:*:*

More vulnerabilities in National Science Foundation Squid Web Proxy

CVE-1999-1481 — Medium (CVSS 5.0): Squid 2.2.STABLE5 and below, when using external authentication, allows attackers to bypass access controls via a…
CVE-2001-0142 — Low (CVSS 1.2): squid 2.3 and earlier allows local users to overwrite arbitrary files via a symlink attack in some configurations.

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