What’s Vulnerable › Vulnerabilities
CVE-2020-29573
- Severity: high (CVSS 7.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 2.7% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2020-12-06 · updated 2026-10-14
- Weakness: CWE-787
Description
sysdeps/i386/ldbl2mpn.c in the GNU C Library (aka glibc or libc6) before 2.23 on x86 targets has a stack-based buffer overflow if the input to any of the printf family of functions is an 80-bit long double with a non-canonical bit pattern, as seen when passing a \x00\x04\x00\x00\x00\x00\x00\x00\x00\x04 value to sprintf. NOTE: the issue does not affect glibc by default in 2016 or later (i.e., 2.23 or later) because of commits made in 2015 for inlining of C99 math functions through use of GCC built-ins. In other words, the reference to 2.23 is intentional despite the mention of "Fixed for glibc 2.33" in the 26649 reference.
Affected products
- GNU C Library (glibc): before 2.23 — fixed in 2.23
- NetApp Cloud Backup: all versions
- NetApp Solidfire Baseboard Management Controller: all versions
- Red Hat Enterprise Linux: 7.0
How to fix
Upgrade to a fixed version: GNU C Library (glibc) 2.23. Check the vendor advisory for mitigations.
References
- https://security.gentoo.org/glsa/202101-20
- https://security.netapp.com/advisory/ntap-20210122-0004/
- https://sourceware.org/bugzilla/show_bug.cgi?id=26649
- https://sourceware.org/pipermail/libc-alpha/2020-September/117779.html
- https://security.gentoo.org/glsa/202101-20
- https://security.netapp.com/advisory/ntap-20210122-0004/
- https://sourceware.org/bugzilla/show_bug.cgi?id=26649
- https://sourceware.org/pipermail/libc-alpha/2020-September/117779.html
- https://cert-portal.siemens.com/productcert/html/ssa-398330.html
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