CVE-1999-1481

Exp

Squid 2.2.STABLE5 and below, when using external authentication, allows attackers to bypass access controls via a newline in the user/password pair.

Published: 1999-12-31 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-1999-1481 is rated High Exploit Risk (63.6/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 3.57%). 2 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-1999-1481

EDB-ID Source Kind Published Link
19567 exploit_db edb 1999-10-25 Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-1999-1481

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 5.76% 3.57% -2.19%
2 2026-01-02 6.36% 5.76% -0.60%
3 2025-04-22 — 6.36% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-1999-1481

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-1999-1481

Affected software / configurations for CVE-1999-1481

Vendor Product Version Raw CPE
national_science_foundation squid_web_proxy 1.0 cpe:2.3:a:national_science_foundation:squid_web_proxy:1.0:*:*:*:*:*:*:*
national_science_foundation squid_web_proxy 1.0novm cpe:2.3:a:national_science_foundation:squid_web_proxy:1.0novm:*:*:*:*:*:*:*
national_science_foundation squid_web_proxy 1.1 cpe:2.3:a:national_science_foundation:squid_web_proxy:1.1:*:*:*:*:*:*:*
national_science_foundation squid_web_proxy 2.1 cpe:2.3:a:national_science_foundation:squid_web_proxy:2.1:*:*:*:*:*:*:*
national_science_foundation squid_web_proxy 2.2 cpe:2.3:a:national_science_foundation:squid_web_proxy:2.2:*:*:*:*:*:*:*

References for CVE-1999-1481

cvelogic Threat Intelligence