CVE-2020-10177Network attack vector

Memory disclosure via unchecked FLI chunk parsing

Published Jun 25, 2020 · Updated Aug 4, 2024

Out-of-bounds reads in Pillow before 7.1.0 allow attackers to disclose process memory by supplying a crafted FLI image for decoding. ImagingFliDecode in libImaging/FliDecode.c parses SS2, LC, copy, and advance fields without checking that reads and copies remain within the encoded input buffer. A user or application must decode the malicious image; successful exploitation exposes data resident in the decoder process, with no demonstrated write or code-execution impact.

CVSS severity7.1
High
EPSS probability1.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds reads in Pillow before 7.1.0 allow attackers to disclose process memory by supplying a crafted FLI image for decoding. ImagingFliDecode in libImaging/FliDecode.c parses SS2, LC, copy, and advance fields without checking that reads and copies remain within the encoded input buffer. A user or application must decode the malicious image; successful exploitation exposes data resident in the decoder process, with no demonstrated write or code-execution impact.

The record

CVE
CVE-2020-10177
Published
Jun 25, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-125, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 25, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:P/I:N/A:N
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
7.1GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1204.002Malicious File

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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