CVE-2015-1821
Description
Heap-based buffer overflow in chrony before 1.31.1 allows remote authenticated users to cause a denial of service (chronyd crash) or possibly execute arbitrary code by configuring the (1) NTP or (2) cmdmon access with a subnet size that is indivisible by four and an address with a nonzero bit in the subnet remainder.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Chrony before 1.31.1 has a heap-based buffer overflow in access configuration, allowing authenticated remote code execution or denial of service.
Vulnerability
A heap-based buffer overflow exists in the access configuration handling of chrony versions before 1.31.1. When an NTP or cmdmon access rule is configured (via chrony.conf or authenticated cmdmon) with a subnet size that is indivisible by four and an address with a nonzero bit in the subnet remainder, it triggers the overflow [1][2].
Exploitation
An attacker must have authenticated access to chrony's cmdmon interface or be able to modify chrony.conf (e.g., as root or equivalent). By crafting a specific subnet configuration with the described properties, they can trigger the heap-based buffer overflow remotely [1].
Impact
Successful exploitation can cause the chronyd process to crash (denial of service) or potentially allow arbitrary code execution with the privileges of the chrony daemon [2].
Mitigation
Upgrade to chrony version 1.31.1 or later, which was released on 2015-04-07 [1]. No known workaround exists; Gentoo's GLSA 201507-01 recommends upgrading [2].
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
4- cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:*
Patches
0No patches discovered yet.
Vulnerability mechanics
AI mechanics synthesis has not run for this CVE yet.
References
5News mentions
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