5.9

CVE-2020-25659: cryptography.io cryptography Covert Timing Channel

Modified
AliasesALPINE-CVE-2020-25659MGASA-2020-0438SUSE-RU-2022:2355-1
Published 11-01-2021Last modified 04-08-2024

Vulnerability summary

CVE-2020-25659 is a medium (CVSS 5.9) Covert Timing Channel vulnerability in cryptography.io cryptography. EPSS estimates a 2.46% chance of exploitation in the next 30 days, higher than 84.4% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.9, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.9/10
010
Medium · v3.1 (NVD)
EPSS score
2.46%
0%100%
Low · +0.03 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 10 · Related 7
OPENSUSE-SU-2024:11223-1OPENSUSE-SU-2024:13819-1OPENSUSE-SU-2026:11468-1RHSA-2021:1608RHSA-2021:2239RHSA-2021:3254

Timeline

  1. 11-01-2021
    PublishedVulnerability first disclosed.
  2. 04-08-2024
    Last modifiedVulnerability information updated.

Description

python-cryptography 3.2 is vulnerable to Bleichenbacher timing attacks in the RSA decryption API, via timed processing of valid PKCS#1 v1.5 ciphertext.

CVSS metrics

7 scores · 5 sources · 3 versions

EPSS trend

Probability

2.46%

Chance of exploitation in the next 30 days

Percentile

84%

Versus all other CVEs

30-day change

Increase +0.03 pp

From 2.43% 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

0 found

No public exploits indexed.

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.

Suse20 products
  • python-cryptography&distro=HPE Helion OpenStack 8< 2.1.4-7.31.1
  • python-cryptography&distro=SUSE Enterprise Storage 5< 2.1.4-7.31.1
  • python-cryptography&distro=SUSE Linux Enterprise Module for Basesystem 15 SP2< 2.8-3.3.1
  • python-cryptography&distro=SUSE Linux Enterprise Module for Basesystem 15 SP4< 3.3.2-150400.16.3.1
  • python-cryptography&distro=SUSE Linux Enterprise Module for Python 2 15 SP2< 2.8-3.3.1
Opensuse3 products
  • python-cryptography-vectors&distro=openSUSE Leap 15.4< 3.3.2-150400.7.3.1
  • python-cryptography&distro=openSUSE Leap 15.2< 2.8-lp152.2.3.1
  • python-cryptography&distro=openSUSE Leap 15.4< 3.3.2-150400.16.3.1
Alpine1 product
  • py3-cryptography< 3.2.1-r0
Cryptography.io1 product
Debian1 product
  • python-cryptography< 3.2.1-1
Mageia1 product
  • python-cryptography< 2.6.1-2.mga7
Oracle1 product
PyPI1 product
  • cryptography< 3.2 | < 3.2.1
Ubuntu1 product
  • python-cryptography< 1.2.3-1ubuntu0.3 | < 2.1.4-1ubuntu1.4 | < 2.8-3ubuntu0.1

9 vendors · 30 products

References

25 links
Show all 25 references