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NVD / CVE Program· CNA mitre

CVE-2021-24115: In Botan before 2.17.3, constant-time computations are not used for certain decoding and encoding operations (base32, base58, base64, and he

Noroxi assessment

Priority: Plan (action score 40/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 1.9% (FIRST EPSS); higher than 79.7% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: botan (Alpine:v3.11) 2.11.0-r4; botan (Alpine:v3.12) 2.11.0-r6; botan (Alpine:v3.14) 2.17.3-r0.

Add it to your regular patch cycle. Upgrade to botan (Alpine:v3.11) 2.11.0-r4; botan (Alpine:v3.12) 2.11.0-r6; botan (Alpine:v3.14) 2.17.3-r0 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In Botan before 2.17.3, constant-time computations are not used for certain decoding and encoding operations (base32, base58, base64, and hex).

CriticalCVSS 9.8 · v3.1—No exploit Fix available
Published
Feb 21, 2021
Updated
Jun 16, 2026
EPSS
1.9% · 79th percentile
CWE
—

Report tools

JSON

Action score

40

Plan

Add it to your regular patch cycle.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 1.9%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2021-24115

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
botan projectbotan

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • botan project botanbefore 2.17.3

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Alpine:v3.11botanbefore 2.11.0-r42.11.0-r4
Alpine:v3.12botanbefore 2.11.0-r62.11.0-r6
Alpine:v3.14botanbefore 2.17.3-r02.17.3-r0
Debian:12botanbefore 2.17.3+dfsg-12.17.3+dfsg-1
openSUSE:Leap 15.2Botanbefore 2.10.0-bp152.4.3.12.10.0-bp152.4.3.1
SUSE:Package Hub 15 SP1Botanbefore 2.10.0-bp152.4.3.12.10.0-bp152.4.3.1
SUSE:Package Hub 15 SP2Botanbefore 2.10.0-bp152.4.6.12.10.0-bp152.4.6.1

Same product

botan project: all records

Other highest-scoring records for the same primary product.

  • CVE-2016-2196Heap-based buffer overflow in the P-521 reduction function in Botan 1.11.x before 1.11.27 allows remote attackers to cause a denial of servi
    41Plan
  • CVE-2016-2195Integer overflow in the PointGFp constructor in Botan before 1.10.11 and 1.11.x before 1.11.27 allows remote attackers to overwrite memory a
    41Plan
  • CVE-2016-9132In Botan 1.8.0 through 1.11.33, when decoding BER data an integer overflow could occur, which would cause an incorrect length field to be co
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2018-12435Jun 14, 2018 · Botan 2.5.0 through 2.6.0 before 2.7.0 allows a memory-cache side-channel attack on ECDSA signatures, aka the Return Of the Hidden Number Pr
    23Monitor
  • ← EarlierCVE-2018-20187Mar 8, 2019 · A side-channel issue was discovered in Botan before 2.9.0.
    23Monitor
  • Later →CVE-2021-40529Sep 6, 2021 · The ElGamal implementation in Botan through 2.18.1, as used in Thunderbird and other products, allows plaintext recovery because, during int
    23Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
alpine:botan2.11.0-r4 · Alpine:v3.11Package registry (OSV)
debian:botan2.17.3+dfsg-1 · Debian:12Package registry (OSV)
opensuse:Botan2.10.0-bp152.4.3.1 · openSUSE:Leap 15.2Package registry (OSV)
suse:Botan2.10.0-bp152.4.3.1 · SUSE:Package Hub 15 SP1Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records