9.8

CVE-2021-3177: debian debian_linux

Modified
AliasesALPINE-CVE-2021-3177MGASA-2021-0064UBUNTU-CVE-2021-3177
Published 19-01-2021Last modified 14-10-2026

Vulnerability summary

CVE-2021-3177 is a critical (CVSS 9.8) vulnerability in debian debian_linux. EPSS estimates a 24.00% chance of exploitation in the next 30 days, higher than 97.8% of scored vulnerabilities. 1 public exploit is recorded.

Priority
Prioritisepublic exploit

Public exploit (reference, Date unknown)

Source freshness unavailable

How is this decided?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
24.00%
0%100%
High · +0.71 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits1reference

Advisory lineage

Upstream 0 · Downstream 28 · Related 19
DLA-2619-1DLA-2919-1DLA-3432-1OPENSUSE-SU-2021:0270-1OPENSUSE-SU-2021:0331-1OPENSUSE-SU-2024:11202-1

Timeline

  1. 19-01-2021
    PublishedVulnerability first disclosed.
  2. 14-10-2026
    Last modifiedVulnerability information updated.

Description

Python 3.x through 3.9.1 has a buffer overflow in PyCArg_repr in _ctypes/callproc.c, which may lead to remote code execution in certain Python applications that accept floating-point numbers as untrusted input, as demonstrated by a 1e300 argument to c_double.from_param. This occurs because sprintf is used unsafely.

CVSS metrics

6 scores · 5 sources · 2 versions

EPSS trend

Probability

24.00%

Chance of exploitation in the next 30 days

Percentile

98%

Versus all other CVEs

30-day change

Increase +0.71 pp

From 23.29% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

1 found
  • referenceUnverified

    Exploit Reference (bugs.python.org)

    Maturity: unknown

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu7 products
  • python2.7< 2.7.12-1ubuntu0~16.04.18 | < 2.7.17-1~18.04ubuntu1.6 | < 2.7.6-8ubuntu0.6+esm10 | < 2.7.18-1~20.04.1
  • python3.4< 3.4.3-1ubuntu1~14.04.7+esm10
  • python3.5< 3.5.2-2ubuntu0~16.04.4~14.04.1+esm1 | < 3.5.2-2ubuntu0~16.04.13
  • python3.6< 3.6.9-1~18.04ubuntu1.4
  • python3.7< 3.7.5-2~18.04.4
Oracle5 products
Debian3 products
Alpine2 products
  • python2< 2.7.18-r1
  • python3< 3.7.7-r2 | < 3.8.2-r2 | < 3.8.5-r1 | < 3.8.7-r1 | < 3.8.7-r2
Mageia2 products
  • python< 2.7.18-1.2.mga7
  • python3< 3.7.9-1.2.mga7
Netapp2 products
Fedoraproject1 product
Python1 product
  • python≥ 3.6.0, ≤ 3.6.12 | ≥ 3.7.0, ≤ 3.7.9 | ≥ 3.8.0, ≤ 3.8.7 | ≥ 3.9.0, ≤ 3.9.1

8 vendors · 23 products

References

43 links
Show all 43 references