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Medium severity5.3NVD Advisory· Published Dec 11, 2016· Updated May 6, 2026

CVE-2016-9850

CVE-2016-9850

Description

An issue was discovered in phpMyAdmin. Username matching for the allow/deny rules may result in wrong matches and detection of the username in the rule due to non-constant execution time. All 4.6.x versions (prior to 4.6.5), 4.4.x versions (prior to 4.4.15.9), and 4.0.x versions (prior to 4.0.10.18) are affected.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Username matching in phpMyAdmin allow/deny rules uses non-constant execution time, enabling attackers to infer valid usernames and potentially bypass rules.

Vulnerability

phpMyAdmin's allow/deny rule mechanism performs username matching using a non-constant-time comparison [1]. This timing side-channel exists in all 4.6.x versions prior to 4.6.5, 4.4.x versions prior to 4.4.15.9, and 4.0.x versions prior to 4.0.10.18 [1]. An attacker can exploit the variable execution time to distinguish between a username that matches a rule and one that does not, leading to incorrect matches or disclosure of which usernames are included in the rules [1].

Exploitation

An attacker with network access to the phpMyAdmin interface can send authentication requests with different usernames and measure the response time. The non-constant comparison allows the attacker to infer whether a given username is part of the allow/deny list, or to trigger a wrong match that could bypass access controls [1]. No prior authentication or special privileges are required to perform this timing analysis [1][2].

Impact

Successful exploitation results in information disclosure: the attacker can learn which usernames are defined in the allow/deny rules. In cases where wrong matches occur, the attacker may be allowed or denied access contrary to the intended configuration, potentially leading to unauthorized access to phpMyAdmin [1]. The confidentiality of username-related rules is compromised, and the integrity of access control decisions is undermined [2].

Mitigation

phpMyAdmin released fixed versions 4.6.5, 4.4.15.9, and 4.0.10.18 on 2016-11-25 [1]. Users should upgrade to one of these versions or later. Gentoo also provides updated packages in GLSA 201701-32 [2]. No workaround is available [2]. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

References
  1. PMASA-2016-61
  2. Multiple vulnerabilities (GLSA 201701-32) — Gentoo security

AI Insight generated on May 23, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.

Affected products

65
  • PhpMyAdmin/phpMyAdmin64 versions
    cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.0:*:*:*:*:*:*:*+ 63 more
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.0:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.1:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.10:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.10.1:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.10.10:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.10.11:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.10.12:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.10.13:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.10.14:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.10.15:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.10.16:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.10.17:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.10.2:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.10.3:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.10.4:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.10.5:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.10.6:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.10.7:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.10.8:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.10.9:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.2:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.3:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.4:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.4.1:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.4.2:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.5:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.6:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.7:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.8:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.0.9:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.0:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.1:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.10:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.1.1:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.11:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.12:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.13:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.13.1:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.14:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.14.1:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.15:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.15.1:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.15.2:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.15.3:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.15.4:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.15.5:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.15.6:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.15.7:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.15.8:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.2:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.3:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.4:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.5:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.6:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.6.1:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.7:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.8:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.4.9:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.6.0:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.6.1:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.6.2:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.6.3:*:*:*:*:*:*:*
    • cpe:2.3:a:phpmyadmin:phpmyadmin:4.6.4:*:*:*:*:*:*:*
    • (no CPE)range: <4.6.5, <4.4.15.9, <4.0.10.18
  • osv-coords
    pkg:rpm/opensuse/phpMyAdmin&distro=openSUSE%20Tumbleweed
    Range: < 4.6.5.2-1.1

Patches

0

No patches discovered yet.

Vulnerability mechanics

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References

4

News mentions

0

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