Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 83.91% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2022
CVE-2021-3781High confidence
A trivial sandbox (enabled with the `-dSAFER` option) escape flaw was found in the ghostscript interpreter by injecting a specially crafted pipe command
Unknown · ghostscript
9.9CriticalCVSS 3.1
Within 7 days
Patch availableCritical technical severity; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityCritical→Operational priority:Critical, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Unknown ghostscript and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Distribution package intelligence
7 package statesRelease-specific package status
Alpine, Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
Repository candidate not checked
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
| Distribution release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Alpine v3.23v3.23 · main | ghostscript | Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected. | 9.54-r1 | Alpine Security Database ↗Source updated 3 Oct 2026 |
| Alpine v3.22v3.22 · main | ghostscript | Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected. | 9.54-r1 | Alpine Security Database ↗Source updated 3 Oct 2026 |
| Alpine v3.21v3.21 · main | ghostscript | Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected. | 9.54-r1 | Alpine Security Database ↗Source updated 3 Oct 2026 |
| Debian trixietrixie · source | ghostscript | Vendor fix publishedDebian records a fixed source-package version for this release. | 9.53.3~dfsg-8 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian bookwormbookworm · source | ghostscript | Vendor fix publishedDebian records a fixed source-package version for this release. | 9.53.3~dfsg-8 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian forkyforky · source | ghostscript | Vendor fix publishedDebian records a fixed source-package version for this release. | 9.53.3~dfsg-8 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian sidsid · source | ghostscript | Vendor fix publishedDebian records a fixed source-package version for this release. | 9.53.3~dfsg-8 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
Critical technical severity; prioritise exposed affected systems while verifying vendor guidance.
Patch available01
What, why and how
A trivial sandbox (enabled with the `-dSAFER` option) escape flaw was found in the ghostscript interpreter by injecting a specially crafted pipe command. This flaw allows a specially crafted document to execute arbitrary commands on the system in the context of the ghostscript interpreter. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
What
A trivial sandbox (enabled with the `-dSAFER` option) escape flaw was found in the ghostscript interpreter by injecting a specially crafted pipe command. This flaw allows a specially crafted document to execute arbitrary commands on the system in the context of the ghostscript interpreter. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
Why
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may execute code or commands in the affected security context.
What
A trivial sandbox (enabled with the `-dSAFER` option) escape flaw was found in the ghostscript interpreter by injecting a specially crafted pipe command. This flaw allows a specially crafted document to execute arbitrary commands on the system in the context of the ghostscript interpreter. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
Why
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may execute code or commands in the affected security context.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Improper Input Validation → execute code or commands in the affected security context
- Attack surface
- Network
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Changed: exploitation can affect a different security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-20 ↗
CWE-20: Improper Input Validation. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SChangedScope: The attack can affect a component governed by a different security authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.- Post-exploitation / living off the land
- After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Affected
- ghostscript: ghostpdl 9.55.0
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 16 Feb 2022 · Last source change 3 Aug 2024, 17:09 UTC · CWE-20 · Improper Input Validation
CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2021-27045
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD modified after enrichment
Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
CVE published
Fixed release or patch reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.