CVE-2025-5702

glibc: Vector register overwrite bug in glibc

Published Jun 5, 2025 CVSS 3.1 · 5.6 Medium EPSS < 1% KEV · Not listed
Description
The strcmp implementation optimized for the Power10 processor in the GNU C Library version 2.39 and later writes to vector registers v20 to v31 without saving contents from the caller (those registers are defined as non-volatile registers by the powerpc64le ABI), resulting in overwriting of its contents and potentially altering control flow of the caller, or leaking the input strings to the function to other parts of the program.

Remediation

Vendor Workaround

One may disable the Power10 optimized string routines in glibc to work around this issue, by setting the glibc.cpu.hwcaps tunable. This can be done by exporting the GLIBC_TUNABLES environment variable like so: export GLIBC_TUNABLES=glibc.cpu.hwcaps=-arch_3_1

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2025-17009 The strcmp implementation optimized for the Power10 processor in the GNU C Library version 2.39 and later writes to vector registers v20 to v31 without saving contents from the caller (those registers are defined as non-volatile registers by the powerpc64le ABI), resulting in overwriting of its contents and potentially altering control flow of the caller, or leaking the input strings to the function to other parts of the program.
Ubuntu USN Ubuntu USN USN-7634-1 GNU C Library vulnerabilities
History
Type Values Removed Values Added
First Time appeared Gnu
Gnu glibc
CPEs cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:*
Vendors & Products Gnu
Gnu glibc
Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Type Values Removed Values Added
Metrics threat_severity

Important

threat_severity

Moderate

Type Values Removed Values Added
Title glibc: Vector register overwrite bug in glibc
Weaknesses CWE-404
References
Metrics threat_severity

None

threat_severity

Important

Type Values Removed Values Added
Weaknesses CWE-665
Metrics cvssV3_1

{'score': 5.6, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description The strcmp implementation optimized for the Power10 processor in the GNU C Library version 2.39 and later writes to vector registers v20 to v31 without saving contents from the caller (those registers are defined as non-volatile registers by the powerpc64le ABI), resulting in overwriting of its contents and potentially altering control flow of the caller, or leaking the input strings to the function to other parts of the program.
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
glibc
Published
Updated
Jun 5, 2025, 8:21 PM
Reserved
Jun 4, 2025, 9:57 PM
Status
Analyzed
Published
Jun 5, 2025, 7:15 PM
Modified
Jun 17, 2026, 9:48 AM
Severity
Moderate
Public date
Jun 5, 2025, 6:23 PM