Buffer overflow in GNU Glibc
CVE-2020-29573
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.027 (85.5th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 85th percentile — 85.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.028 · newest: 0.027 · change: -0.001
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- sourceware.org/bugzilla/show_bug.cgi (Patch, Third Party Advisory, Issue Tracking)
- sourceware.org/pipermail/libc-alpha/2020-September/117779.html (Patch, Third Party Advisory)
- security.netapp.com/advisory/ntap-20210122-0004/ (Third Party Advisory)
- security.gentoo.org/glsa/202101-20 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-29573?
- CVE-2020-29573 is a high-severity vulnerability in GNU Glibc, classified under Out-of-bounds Write. CVSS score: 7.5/10. Published 2020-12-06.
- How severe is CVE-2020-29573?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2020-29573 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.