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CVE-2024-53271· NVD / CVE Program· CNA GitHub_M

HTTP/1.1 multiple issues with envoy.reloadable_features.http1_balsa_delay_reset in envoy

Noroxi assessment

Priority: Monitor (action score 28/100)

  • 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: 0.61% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • No fixed version is recorded, but the references include a patch (commit or PR) link.

Low priority for now. See the fix and affected versions sections below.

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

Envoy is a cloud-native high-performance edge/middle/service proxy. In affected versions envoy does not properly handle http 1.1 non-101 1xx responses. This can lead to downstream failures in networked devices. This issue has been addressed in versions 1.31.5 and 1.32.3. Users are advised to upgrade. There are no known workarounds for this issue.

HighCVSS 7.1 · v3.1—No exploit No fix recorded
Published
Dec 18, 2024
Updated
Jun 17, 2026
EPSS
0.6% · 48th percentile

Report tools

JSON

Action score

28

Monitor

Low priority for now.

CVSS
28 / 40 · 7.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.6%

CISA SSVC decision

Exploitation
proof of concept
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
7.1
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

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

Follow CVE-2024-53271

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
envoyproxyenvoy

Affected versions

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

  • envoyproxy envoy1.31.0 and later · before 1.31.5
  • envoyproxy envoy1.32.0 and later · up to 1.32.3 inclusive

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • envoyproxy envoy

    • >= 1.31.0, < 1.31.5, >= 1.32.0, < 1.32.3affected

Same product

envoyproxy: all records

Other highest-scoring records for the same primary product.

  • CVE-2024-30255HTTP/2: CPU exhaustion due to CONTINUATION frame flood
    56Plan
  • CVE-2024-27919HTTP/2: memory exhaustion due to CONTINUATION frame flood
    56Plan
  • CVE-2021-29492Bypass of path matching rules using escaped slash characters
    53Plan
  • CVE-2019-15226Upon receiving each incoming request header data, Envoy will iterate over existing request headers to verify that the total size of the head
    49Plan
  • CVE-2019-9901Envoy 1.9.0 and before does not normalize HTTP URL paths.
    41Plan
  • CVE-2019-18802An issue was discovered in Envoy 1.12.0.
    40Plan

Remediation

Which version to upgrade to

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

No fix version is recorded for this entry. Check the references for vendor advisories.

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.

  • CVE-2024-532690 days apartHappy Eyeballs: Validate that additional_address are IP addresses instead of crashing when sorting in envoy
    30Monitor
  • CVE-2024-532700 days apartHTTP/1: sending overload crashes when the request is reset beforehand in envoy
    30Monitor
  • CVE-2024-4580790 days apartoghttp2 crash on OnBeginHeadersForStream in envoy
    30Monitor

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.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

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

Weakness class (CWE)

CWE-670 · Always-Incorrect Control Flow Implementation

CVSS vector

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

nvd-secondary

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

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

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

All records