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PatchSiren cyber security CVE debrief

CVE-2016-6264 Uclibc CVE debrief

CVE-2016-6264 is a high-severity denial-of-service issue in the ARM memset implementation used by uClibc and uClibc-ng. A negative length value can trigger a crash, making affected libc builds a stability risk for systems that depend on them.

Vendor
Uclibc
Product
CVE-2016-6264
CVSS
HIGH 7.5
CISA KEV
Not listed in stored evidence
Original CVE published
2017-01-27
Original CVE updated
2026-05-13
Advisory published
2017-01-27
Advisory updated
2026-05-13

Who should care

Teams maintaining or shipping systems that use uClibc or uClibc-ng, especially ARM-based embedded or appliance builds, should review exposure and patch status.

Technical summary

NVD describes an integer signedness error in libc/string/arm/memset.S in uClibc and uClibc-ng before 1.0.16. If a negative length value reaches memset, the affected code can crash, producing a denial of service. NVD assigns CVSS 3.1 vector AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (7.5 High). The record lists uClibc as affected and uClibc-ng as affected through versions before 1.0.16.

Defensive priority

High. The flaw can take down affected processes or devices, and libc fixes often require rebuilds or firmware updates rather than simple package upgrades.

Recommended defensive actions

  • Inventory any products or firmware that ship uClibc or uClibc-ng, with special attention to ARM builds.
  • Upgrade uClibc-ng to 1.0.16 or later; confirm whether your uClibc-based distribution has an equivalent vendor fix.
  • Rebuild and redeploy affected images or firmware, since libc fixes are often delivered at the image level.
  • Review code paths that pass lengths into memset and add input validation where application logic can supply negative or untrusted values.
  • Test crash resilience in staging after patching and monitor for unexpected process exits or watchdog resets.

Evidence notes

The supplied corpus ties this CVE to the official NVD/CVE records and vendor/patch references. NVD marks uClibc as vulnerable and uClibc-ng as vulnerable before 1.0.16. The reference list includes uClibc-ng vendor advisories/release notes and OSS-security patch discussions dated May through July 2016. No Known Exploited Vulnerabilities (KEV) entry was provided. The CVE was published on 2017-01-27 and later modified on 2026-05-13; those dates are used here for disclosure timing context only.

Official resources

Publicly disclosed in the CVE/NVD record on 2017-01-27; supporting vendor advisories and patch discussions in the reference list date to May-July 2016.